Mosquito fossil found so well-preserved still has blood in its stomach.

Scientists discover mosquito fossil so well-preserved that it still has blood in its stomach

  • The mosquito perished soon after feeding in the Middle Eocene and its body has been trapped in shale ever since
  • A team of international researchers used non-destructive mass spectrometry to create a chemical picture of the mosquito’s stomach contents
  • The find extends the fossil record of blood-feeding in this family of insects by 46 million years
Blood sucked by a mosquito that died 46 million years ago has been discovered by scientists.Researchers used a new technique to determine the nature of the animal’s last meal to prove that the insects have been feeding on blood all this time and could even have feasted on dinosaurs.The mosquito that was discovered perished soon after feeding in the Middle Eocene and its body has been trapped in shale ever since.

Researchers used a new technique to determine the nature of the mosquito's last meal

Researchers used a new technique to determine the nature of the mosquito’s last meal to prove that the insects have been feeding on blood all this time and could even have feasted on dinosaurs. The creature’s fossilised body (pictured) has been trapped in shale for 46 millions years

The animal died when the spectacular mountain ranges in Montana, where it was dug up, had just finished forming.

The ancient insect was so well-preserved because it had been trapped in shale – a type of mudstone in which organic remains decompose much more slowly – and the soft mud material that surrounded it compressed the creature’s body without distorting it.

The fine grain size of shale also preserves more details and the process of fossilisation is much like holding the fossil flat and pressing it like a book protects a dried flower.

Paleobiologist Dr Dale Greenwalt, a researcher at the Smithsonian’s National History Museum, who led the study, used a state-of-the-art technology called non-destructive mass spectrometry to produce a detailed chemical picture of the mosquito’s stomach contents.

The findings show the insects have been feeding on blood for millions of years and around 14,000 living insect species including fleas, ticks and modern mosquitoes feed on blood today.

Although this feeding strategy appears to have evolved independently across a variety of animals, fossil evidence of this behaviour is extremely rare.

The find extends the fossil record of blood-feeding in this family of insects by 46 million years, according to Dr Ralph Harbach, a researcher at the Natural history Museum in London who was involved with the study.

Dr Dale Greenwalt used non-destructive mass spectrometry

Dr Dale Greenwalt used non-destructive mass spectrometry to produce a detailed chemical picture of the mosquito’s stomach contents. The findings show the insects have been feeding on blood for millions of years and around 14,000 living insect species including fleas, ticks and modern mosquitoes (pictured) feed on blood today

After finding high levels of iron in the fossilised insect’s abdomen, the researchers analysed the specimen and identified the source as haem – the protein in the blood responsible for the transport of oxygen.

Although large and fragile molecules such as DNA generally do not survive fossilisation, the mosquito proves certain complex organic molecules such as haem can be preserved.

It was one of two mosquitoes discovered in the shale deposits that reveal just how remarkably little the parasites have changed in the last 46 million years.

The new fossils – one female and the other male – are so detailed scientists were able to determine they represent two previously unknown species.

The female, named Culiseta lemniscata, had eaten the blood meal. The male has been named Culiseta kishenehn.

Their fossils contain details as intricate as wing veins, sexual organs, scales and hair-like structures on the wings.

Richard Attenborough in the film is pictured

Dr Greenwalt said it’s not surprising that it is the first discovery of its kind despite the misconception of dinosaur DNA recovery from mosquitoes preserved in amber popularised by Jurassic Park twenty years ago – Richard Attenborough in the film is pictured

Dr Greenwalt and colleagues, whose findings are published in Proceedings of the National Academy of Sciences, said the preservation of the fossil was ‘extremely improbable’.

‘The insect had to take a blood meal, be blown to the water’s surface and sink to the bottom of a pond or similar structure to be quickly embedded in fine sediment – all without disruption of its fragile distended blood-filled abdomen.’

He said it is not surprising that it is the first discovery of its kind despite the misconception of dinosaur DNA recovery from mosquitoes preserved in amber popularised by Jurassic Park twenty years ago.

‘The existence of this rare specimen extends the existence of blood-feeding behaviour in this family of insects 46 million years into the past,’ Dr Greenwalt said.

‘This is the only known fossil of a blood-engorged mosquito ever found and represents the first clear evidence that some organic molecules can be preserved in a fossil of this age.

‘We made the assumption that genetic material like DNA was not preserved. We didn’t even attempt to look at it because DNA degrades very quickly.

‘Without question there are probably other things contained in this fossil. We just don’t know what they might be,’ he added.

Photons on demand now possible on hair’s width optical chip – News and Events – University of Sydney

A breakthrough in photonics that will help create extremely compact optical chips, a hair’s width in size and delivering a photon at a time, has been achieved by researchers from the University of Sydney.

“This result has applications in the development of complex quantum technologies, including completely secure communications, quantum measurement, the simulation of biological and chemical systems and of course quantum computing,” said Dr Alex Clark, leader of the research team from the Australian Research Council Centre of Excellence for Ultrahigh Bandwidth Devices for Optical Systems (CUDOS).

Carried out at the University of Sydney’s School of Physics, the research is published in Nature Communications today.

It is part of a wider collaboration involving Australian and international universities, including Macquarie University, the University of St Andrews and the University of York, as well as the Australian Defence Science and Technology Organisation (DSTO).

Photons are single particles of light that can readily carry quantum information. The importance of being able to develop a chip that can deliver one photon at a time at very high rates is to provide scalability for the extraordinary diversity of quantum technologies that could enhance computing and communication infrastructure.

Scalability refers to the ability to use many photon sources in parallel to carry out complicated tasks.

“It is easy for us to generate photons at high rates, but it’s much harder to ensure they come out one by one because photons are gregarious by nature and love to bunch together,” said lead author of the Nature Communications article Matthew Collins, a PhD student from CUDOS at the University of Sydney.

“For that reason the quantum science community has been waiting over a decade for a compact optical chip that delivers exactly one photon at a time at very high rates.”

In fact, the creation of a single photon in an optical circuit has been possible for some years, but previous demonstrations have been difficult to implement and scale up or have been excessively noisy. This has limited the single photon technology to being either very slow or having a high probability of error.

“We’ve shown how multiple imperfect sources of photons on a single chip can be combined to produce a much higher quality source,” said Dr Clark.

The photons here are generated from a pulsed laser. “A key breakthrough for this research was the CUDOS development of photonic chips that slow light,” said Professor Ben Eggleton, CUDOS Director and co-author of the research. “This makes single photon generation more likely, reducing energy demands and allowing extremely compact devices with lengths no longer than 200 microns, the width of a human hair.”

“The smaller these systems are, the more we can fit onto a chip, and the more we can fit onto a chip the more likely we are to guarantee a single photon when we want it,” said co-author Associate Professor Michael Steel (Macquarie University), CUDOS’ Science Leader for Quantum Integrated Photonics.

The CUDOS research team at the University of Sydney: (L to R) Dr Alex Clark, Michael Steel, Professor Benjamin Eggleton, Jiakun He, Shayan Shahnia, Dr Chunle Xiong, Trung Vo and Matthew Collins.

The next step is to integrate all the components of this scheme onto a single chip so that an on-demand ‘push button’ single photon source can be deployed in future photonic quantum technologies.

“This result presents a major milestone for the Centre and for the field. We are especially pleased with the successful collaboration between CUDOS and DSTO,” said Professor Eggleton.

Dr Alexander Zelinsky, Chief Defence Scientist and head of the Defence Science and Technology Organisation, acknowledged the importance of collaboration with the University of Sydney and the CUDOS program. “Australia’s research in photonic devices is world leading, and we are delighted to collaborate in the area of quantum photonics, which promises revolutionary quantum devices for secure communications”.

Scientists Find the Coldest Temperatures where Simple Life can Liwe « From Quarks to Quasars

Have you ever woken up to a morning so cold you thought to yourself “I don’t see how anything lives in this type of cold”? Well, scientists have finally discovered the lowest temperature where simple life can grow and flourish. We aren’t talking about basic surviving (like the famous tardigrade), we’re talking living, breathing life going about doing its business eating, sleeping, and just general awesome living in the microscale.


And, that magic number is…

*drum roll*

-20 °C (or -4 °F)

At minus 20, single celled organisms dehydrate and either die or go into hibernation. The point is they stop their biological functions, their life cycle goes into standby mode, and the cell waits for conditions that are more favorable before doing anything. Since the organisms don’t eat or reproduce, -20 degrees °C is officially the lowest temperature limit for life on our little world.

I’ll reiterate that this does not concern the process of vitrification. Vitrification is the process of “controlled dehydration” or “controlled freezing” that a cell undergoes when temperatures get too cold. When a cell vitrifies, scientists don’t consider it a living entity because it can’t reproduce or metabolize, or generally do anything resembling life processes. Organisms can survive MUCH lower temperatures when vitrified, but are just worthless until the temperature warms up.

More complex organisms (I’m talking to you people who live in freakishly cold places) can survive lower temperatures because they are able to regulate the our internal temperatures and the environment around our skin to some extent. We are more versatile, but it’s cheating to compare a human to a single celled organism.

Professor Andrew Clarke, from the NERC’s British Antarctic Survey, elaborated, “Bacteria, unicellular algae and unicellular fungi – of which there are a huge amount in the world-are free-living because they don’t rely on other organisms. Everything else, like trees and animals and insects, has the ability to control the fluid that surrounds their internal cells. In our case it’s blood and lymph. In a complicated organism, the cells sit in an environment that the organism can control. Free-living organisms don’t have this; if ice forms in the environment they are subject to all the stresses that implies.”


An unexpected side effect of this study helped to explain why freezing your food is a great method for long-term storage. Most commercial freezers operate around -20 °C, so bacteria is unable to reproduce and feast on your food. This gives scientists a mechanism for the reason why domestic freezers work really well for preserving your perishables.

Anti-cancer vaccine for Laos.

Khonekham with health card with health card
Khonekham holds her health card showing she has received her first dose of the HPV vaccine

A programme to vaccinate girls against the virus that causes cervical cancer has begun in Laos, South East Asia.

It’s one of nearly a dozen developing nations where the HPV vaccine is being introduced in the coming year as part of a scheme to enable poorer countries to benefit from the newest vaccines.

It is five years since the jab was first offered to girls in the UK.

The project is being organised with the support of the Global Alliance for Vaccines and Immunisation (Gavi).

“Start Quote

The HPV vaccine represents a very significant commitment to women’s health in the coming decades.”

Helen Evans GAVI Alliance

The vaccine protects against the sexually transmitted human papillomavirus – preventing the infections that cause 70% of cases of cervical cancer.

‘Proud’ to be immunised

Khonekham Sirivong, 13, stood patiently in the queue of girls waiting for the HPV vaccine.

This was a poignant moment for her and Somsouk, her aunt, one of the nurses, under the shelter of trees in the school grounds.

Somsouk’s mother – Khonekham’s grandmother – died from cervical cancer. The two helped nurse her through years of illness.

“I remember she was in a lot of pain,” said Khonekham. “The family did everything it could, but she died. I am very proud to be immunised – and to have the HPV vaccine free of charge.”

Vaccine ‘crucial’

Cervical cancer is a far bigger cancer killer in developing countries because most lack a national screening programme, which can detect pre-cancerous changes in the cervix, enabling timely early treatment.

In Laos, most cases are discovered too late. Cancer treatment in the world’s poorest nations is also limited. Laos has no radiotherapy. Patients who can afford it are sent to Thailand.

“Approximately 275,000 women die every year from cervical cancer and over 85% of those deaths are in the developing world,” said Helen Evans, Gavi deputy chief executive.

“The number of deaths is projected to rise dramatically, so that’s why it is absolutely crucial that this vaccine is introduced.

“The HPV vaccine represents a very significant commitment to women’s health in the coming decades.”

survivor of cervical cancer
“I feel lucky to be alive,” said Sommay Khamkeomany

I have visited a lot of hospitals, in many of the world’s poorest countries – from Sierra Leone to Malawi and Bangladesh. But they have rarely been as crowded at Setthathirath hospital in Vientiane.

A senior oncologist, Dr Keokedthong Phongsavan, showed me round one of the wards, where the beds had spilled out into the corridor and were squeezed next to each other to accommodate more patients.

Sent home to die

However, it was not the overcrowding, but the limited treatment options that presented the biggest problem.

“I feel helpless,” said Dr Phongsavan. “Patients are often diagnosed very late, and then there is often very little I can do to help them. I have to send them home to die.”

The mortality rate for cervical cancer in Laos is six times that of the UK. But there are some success stories. Sommay Khamkeomany was diagnosed with cervical cancer last year when she was just 32.

She had surgery and has now been told she has a 95% chance that her cancer will not recur.

“I have two girls aged five and three,” said Mrs Khamkeomany. “When they are old enough I will ensure they have the HPV vaccine – and fortunately I should still be here to see that happen. I feel lucky to be alive.”


The HPV jab is the most expensive of all childhood vaccines. A course of three injections can cost more than £200 privately in the UK and other wealthy countries. It was well beyond the reach of most developing nations until Gavi negotiated a price of less than £10.

Like other Gavi-supported countries, Laos has to make a token financial contribution, but also has to supply the nurses and organise distribution of the vaccine.

The two-year pilot project in Laos involves about 20,000 girls being immunised. If successful, it will lead to a national roll-out of the jab.

By 2020, Gavi hopes to have supported HPV immunisation of more 30 million girls in over 40 countries.

The benefits, in terms of lives saved, won’t be felt for decades, but it represents a milestone in the promotion of women’s health.

The nun teaching taekwondo to sick children.

Sister Linda Sim gave up taekwondo when she joined a convent. Years later, she’s dusted off her black belt at a Singaporean hospice to teach children recovering from cancer.

When she was much younger, Linda Sim wanted to join the army, but was told she was too small.

“Next I thought I could be a policewoman – to protect people,” she says, but she didn’t make the weight requirements for the police force, either.

Instead, she discovered taekwondo in 1971, and it seemed to fulfil her need to help other people. “If I had a black belt I thought I could be a bodyguard and protect somebody.” Within a few years, she achieved just that.

Though the sport gave her great mental strength, she didn’t find a practical use for her martial art for more than three decades.

Much to the chagrin of her parents, Sim met the Franciscan Missionaries of the Divine Motherhood, and decided to join them by becoming a Catholic nun.

“Being the only daughter, my mum was very upset when I said I would give my life to God and be a missionary,” she says. Her parents had hoped she would provide them with grandchildren.

Since the group’s headquarters were on the other side of the world in Britain, she would disappoint them further by leaving Singapore.

“I spent 17 years in England and three more in Africa, where I ran a hospital in Zimbabwe,” she says.

During her absence, a relationship developed between the Singapore Taekwondo Federation and Mount Alvernia hospital in the centre of the country.

Ming Wong, secretary general of the federation explains that an employee of the hospital thought some of its patients – young children being treated for cancer – could benefit from the sport. They were “stuck inside playing snakes and ladders”, she says, and the organisation agreed to provide training sessions for them.

Linda Sim with students

It was not until 2004, when Sim’s mother was diagnosed with Alzheimer’s disease, that she felt she had to return to Singapore.

When she saw the classes taking place, she knew she wanted to be involved. “That was what I had to leave behind in order to be a sister, and so I thought ‘now I’m reunited’,” she says.

Today she runs a weekly class for about 20 people, all of whom have brain tumours or childhood leukaemia. Most are young children, although three are now in their 20s, having trained under Sim for many years.

One of the older students, Ng Wei Hau, was diagnosed with a brain tumour at the age of 12 and given just six months to live by his doctors. “When I first met him he was in a wheelchair. When he reached 21 he was walking with a frame, when he reached 23 he had a stick, and now he walks unaided,” she says. Despite being partially deaf and blind, Wei Hau became a black belt last year under Sim’s tutelage.

“These children try to do their best however they can, despite their sickness,” says Wong. “I think because they want to live life for the fullest because they want to enjoy whatever time they have.”

The federation’s charitable work is not just limited to children from the hospital. The organisation works with children’s homes and other disadvantaged groups to offer free taekwondo classes to others who would not usually come into contact with the sport.

For Sim, religion is central to her motivation. Whereas most sisters teach religious education in quite a traditional way, she thinks the taekwondo classes allow her to lead by example instead.

“For me I can actually be a presence and a witness to God’s love without actually quoting scripture,” she says. “It gives me a lot of peace and satisfaction. It’s about evangelising without having to mention going to church.”

Scientists Recreate The Sense Of Touch With Direct-To-Brain Electrical Signals .

We’ve seen some very cool prosthetic arms recently, including ones people are able to control—just as they control biological arms—with their thoughts. So what’s one of the next great frontiers for prosthetics? Letting people experience touches through them, too.

photo of an experimental prosthetic arm

The human sense of touch does a lot more than let people enjoy fresh sheets or soft kitties. It’s also crucial for helping people judge how hard to hold stuff they want to pick up, or whether they’ve got a good grip on something slippery. In a feature published earlier this year, Nature News talked with one prosthetic arm user, Igor Spetic, who accidentally broke dishes and bruised fruit he tried to hold with his device. If he had a prosthesis that had a sense of touch, he told Nature News, “I’d probably lay everything on the countertop and just start grabbing stuff. I’d be so excited.”

Now one research group is reporting a major step toward a touchy-feely prosthetic. A team of researchers from the University of Chicago and Johns Hopkins University performed a series of experiments that showed they could send electrical signals directly to the brains of rhesus macaques and that the macaques were able to interpret the signals as touches on different parts of their hands. Another series of experiments showed rhesus macaques could interpret different direct-to-brain signals as touches of varying pressure. A third explored whether direct-to-brain signals work quickly enough to be able to accurately tell macaques when a prosthetic is touching something and when it stops the touch. (The signals seem to move too slowly to be totally accurate, but the researchers thought of some workarounds, which they discussed in a paper they published today in the Proceedings of the National Academy Sciences.)

The macaques were quickly able to interpret electrical brain stimulation as analogues to physical touches.

The team will surely work to incorporate those findings into a device. For one thing, some of the researchers’ experiments actually involved a prosthetic finger that sent signals to the research monkeys‘ brains. For another, Johns Hopkins University is working on a prototype that’s the most sophisticated touch-enabled prosthesis in the world, with more than 100 sensors, Nature News reports.

There was one especially cool thing the Chicago-Johns Hopkins team demonstrated. While it’s impossible to know exactly what the monkeys feel when they get electrical buzzes to their brains, one series of experiments showed the animals were quickly able to interpret electrical brain stimulation as analogues to physical touches.

First, the researchers taught rhesus macaques to look either left or right after feeling two presses into their hands—say, pressure on the index finger, and then pressure on the pinky finger. After running several trials to make sure the monkeys learned the press-look game as well as they could, the researchers stimulated parts of the monkeys’ brains they’d learned corresponded with different parts of the monkeys’ hands. The two macaques in whom the researchers tested this looked in the correct direction 81 percent and 72 percent of the time, the very first time researchers sent electrical signals to their brains.

This research could help scientists develop touch-enabled prosthetics that send signals that are intuitive for people to interpret, the researchers wrote in their paper.

It’ll be years yet before technology like this will show up in prosthetics for people, however. It is invasive, requiring wiring to the brain, so researchers will have to do a lot to show it’s safe and durable. (Nobody wants to have to undergo frequent brain implants for tune-ups or software updates.) It’s also not clear yet whether electrical signals sent to the brain are able to reproduce touches as specific as human or monkey skin is able to feel. The electric signals could be lower resolution than true touches.

New topological insulator materials may speed future semiconductor chips

Imagine if the “information superhighway” had HOV lanes so that data could be stored, processed and disseminated many times faster than possible with today’s electronics. Researchers in the United States and China have teamed to develop such a speedway for future devices, an exotic type of electrical conductor called a topological insulator (TI). In a new paper in the journal AIP Advances, the international collaborators report that they grew two types of TI materials inside an ultra-high vacuum chamber on both smooth and rough surfaces and then evaluated their abilities to transport electrons.

A TI harnesses not only the charge of electrons, but also their spin and magnetic properties. The interior of this unusual structure is an insulator, something that blocks the flow of current, while the surface acts as a highly efficient conductor of electricity. So efficient, in fact, that the electrons never deviate from their path.

“This makes the TI promising for applications such as future high-speed, dissispationless [does not involve energy dissipation] computers where massive quantities of information would be carried by electrons in quantum channels,” said physicist and corresponding author Jian Wang at Peking University‘s International Center for Quantum Materials. “Avoiding the scattering of that occurs in today’s computers would keep high-speed devices from experiencing chip overheating, destruction of the data stream, and a slowdown of operational speed.”

In their study, the researchers grew two types of TI materials, bismuth telluride (Bi2Te3) and antimony telluride (Sb2Te3), one atomic layer at a time on both vicinal (rough) and non-vicinal (smooth) forms of a substrate material commonly used by the semiconductor industry, gallium arsenide (GaAs).

“Higher quality, better-electron-conducting TI films were grown on the smoother surface substrate and that was unexpected,” says Timothy Morgan, co-author and nanotechnologist at the Arkansas Institute for Nanoscale Material Sciences and Engineering. “Typically, rough spots would provide anchor points for film growth kind of like putting the first pieces of a tile floor up against a wall so that the rest fall in alignment. This new finding tells us we need to do more investigations of the growth mechanisms involved.”

Now that the researchers have shown that they can grow high-quality TI materials on industry standard substrates, they say the next step is to put them to work. “We will try to design and fabricate some fundamental devices using TI materials to see how well they perform tasks such as electronic switching and photodetection,” says Zhaoquan Zeng, lead author an and postdoctoral researcher at Ohio State University‘s Electrical and Computer Engineering Department.

The article, ” Molecular beam epitaxial growth of Bi2Te3 and Sb2Te3 topological insulators on GaAs (111) substrates: a potential route to fabricate p-n junction” by Zhaoquan Zeng, Timothy A. Morgan, Dongsheng Fan, Chen Li, Yusuke Hirono, Xian Hu, Yanfei Zhao, Joon Sue Lee, Jian Wang, Zhiming M. Wang, Shuiqing Yu, Michael E. Hawkridge, Mourad Benamara, and Gregory J. Salamo, appears in the journal AIP Advances.

Source: American Institute of Physics

14 Google Tools You Didn’t Know Existed

Routine Urinalysis Not Helpful After Blunt Abdominal Trauma.

Routine urinalysis after blunt abdominal trauma won’t help find urogenital injury, Dutch researchers say.

“With the advancements made in CT scanning, there is now much greater accuracy in the detection (or ruling out) of injury to the urogenital system,” Dr. J. Carel Goslings from Academic Medical Center in Amsterdam told Reuters Health.

“In this study,” Dr. Goslings added, “we found the value of the routine performance of urinalysis in patients with a blunt trauma mechanism to be limited.”

The retrospective study involved 1815 patients. Most patients — 1031, or 57% — also had imaging studies, according to a paper online September 16th in Emergency Medicine Journal.

Among the patients who had imaging studies done, 795 (77%) had no hematuria, 220 (21%) had microscopic hematuria, and 16 (2%) had macroscopic hematuria.

Of the 220 patients with microscopic hematuria, eight had abnormal urogenital imaging studies, but only three of the eight had clinical consequences. Another eight patients with microscopic hematuria did have clinical consequences despite normal-looking imaging.

There were 332 patients who had urine collected but no imaging studies. In this group, 278 patients (84%) had no hematuria. In the 54 patients (16%) who did have microscopic hematuria, there were no clinical consequences, according to the authors.

Two hundred sixty-eight patients (15%) had urogenital imaging but no urinalysis. Only 10 had abnormal findings; four of the 10 had clinical consequences.

Ten percent of patients had neither urine collection nor imaging.

“The potential danger of performing urinalysis without imaging is to miss clinically relevant injuries (e.g., bleeding sites in the kidney parenchyma), which can only be shown by imaging,” the authors wrote. “Bypassing urinalysis and going straight for imaging…results in clinical consequences in 1.5% of the patients (4 out of 268). This is comparable to the percentage of clinical consequences in the patients who receive both urinalysis and imaging (2%; 22 out of 1031).”

They added, “The remaining 0.5% difference in clinical consequences consists of relatively minor consequences such as additional imaging and re-evaluation at the outpatient department, and this indicates little added value of the performance of urinalysis.”

Dr. Goslings told Reuters Health that the researchers “advise omitting this investigation as a routine part of the assessment of trauma patients, given that (good) imaging facilities are available in the hospital.”

But in specific circumstances, urinalysis might still be appropriate. Repeating by email some points from the paper, Dr. Goslings wrote, “In particular, patients with specific trauma mechanisms (e.g., fall from height, fall from horse or direct blow to the flank) or patients with a suspicion of pelvic (ring) injuries or thoracolumbar spinal cord injuries might benefit from urinalysis.”

“Future studies should focus on identifying the subgroups of patients in whom urinalysis is helpful,” Dr. Goslings added.

Probiotics Likely Do Little to Soothe Colicky Babies.

Sad news for sleep-deprived parents: probiotics may not quiet their colicky babies, a new meta-analysis suggests.

Evidence is still insufficient “to support probiotic use to manage colic, especially in formula-fed infants, or to prevent infant crying,” lead author Valerie Sung, MPH, and colleagues report in an articlepublished online October 7 in JAMA Pediatrics.

Colic, defined as excessive crying or fussing for no apparent reason, affects up to 20% of infants younger than 3 months, but its etiology remains unclear, write Sung, from the Murdoch Children’s Research Institute and Royal Children’s Hospital, Parkville, Australia, and coauthors. Some evidence points to an association with food allergies, but other data show differences in gut microflora between babies with and without colic. “The logical next step is to determine whether intervening to alter gut microbiota can effectively prevent or reduce infant crying,” the authors write.

Use of probiotics, products that use live microorganisms to confer health benefits, can change the infant gut environment and has been shown to suppress intestinal inflammation, strengthen mucosal barriers, and modulate gut contractility, any of which could produce uncomfortable symptoms and contribute to an infant’s irritability. In a meta-analysis, the authors sought to determine whether probiotics were better than no or standard treatment at reducing the duration of infant crying or distress, number of episodes of crying or distress, and proportion of infants with colic (crying or fussing for at least 3 hours a day, at least 3 days a week, for at least 1 week).

The authors identified 12 randomized, clinical trials including 1825 infants: 271 term babies with colic, 1534 term infants without colic, and 20 preterm newborns without colic. Five studies focused on probiotics specifically to manage colic, and 7 examined the use of probiotics to reduce infant crying. Some of the studies examined use of a single product, whereas others looked at the use of multiple products administered together. The products were administered as drops, capsules, or formula in a range of doses. All of the studies were placebo-controlled. Daily infant crying time was the most common reported outcome. The analysis was conducted according to guidelines from the Cochrane Handbook for Systematic Reviews of Interventions.

Mean daily crying time was significantly less in 2 of 7 trials in which probiotics were used to prevent colic; there were no differences between probiotics and placebo in the other 5 trials. Of the 5 trials examining probiotics in the management of colicky episodes, probiotics were significantly more effective than placebo in 3 trials in which Lactobacillus reuteri was administered in drops to breast-fed, full-term infants. Compared with placebo, probiotics were associated in those trials with a median reduction in daily crying time of 62.10 minutes (95% confidence interval [CI], −85.82 to −44.38 minutes; P < .001), but there was substantial heterogeneity among the trials. The authors conclude that the effect of probiotics in treating colic remains unclear because of the difficulty in comparing studies that examined vastly different products on different populations.

At least one outside expert agrees with this conclusion, despite some reservations about the authors’ methods. “The definition of colic was not rigorously controlled; there is likely to be no single cause of colic and no single treatment that is effective,” said Frank R. Greer, MD, professor of pediatrics, Wisconsin Perinatal Center, Meriter Hospital, Madison, Wisconsin. “The dosages and specific probiotic preparations were too variable[, and] whether they were given prenatally or not to both mother and infant after delivery also was extremely variable.” In addition, Dr. Greer told Medscape Medical News, “the authors did not use a validated methodology for recording the primary outcome, which was length of crying time.”

In Dr. Greer’s opinion, there is currently no place for probiotics in the management of infant colic. In contrast, he said, it has no serious adverse effects, “other than it adds unnecessarily to the cost of infant formula.”