Prebiotics in infant formula could improve learning and memory and alter brain chemistry

January 17, 2018, University of Illinois at Urbana-Champaign
Researchers at the University of Illinois find that prebiotics in infant formula could improve learning and memory and alter brain chemistry. Credit: Lauren D. Quinn, University of Illinois

Nearly every American who has become a parent in the last decade has heard the slogan, "breast milk is best," and has likely been encouraged to offer breast milk to newborns. Among other things, breast milk contains natural sources of prebiotics: small, indigestible fiber molecules that promote the growth of good bacteria in the baby's gut. Yet for many families, breastfeeding is difficult or impossible. Fortunately, modern infant formulas are getting closer to the real thing with the help of University of Illinois researchers.

In a recent study from the Piglet Nutrition and Cognition Lab at U of I, scientists worked with piglets to show prebiotics included in can enhance memory and exploratory behavior.

"When we provide prebiotics in formula, our results confirm that we can not only benefit gut health, which is known, but we can also influence development," says Ryan Dilger, associate professor in the Department of Animal Sciences, Division of Nutritional Sciences, and Neuroscience Program at U of I. "We can actually change the way piglets learn and remember by influencing bacteria in the colon."

Piglets are widely considered a more informative model for human infants than mice and rats; their digestive systems, behavioral responses, and brain development are remarkably similar to human infants. Therefore, researchers are increasingly turning to piglets to test hypotheses in pre-clinical trials related to human health, especially in the context of gut microbes and brain development.

"There hasn't been a lot of work looking at the gut-brain axis in humans, but a lot of rodent work is showing those connections. This is taking it to an animal model that is a lot closer to human infants and asking if that connection still exists and if we can tease out possible mechanisms," says Stephen Fleming, lead author of the study and a doctoral student in the Neuroscience Program at U of I.

In early 2016, Dilger and his colleagues worked with piglets to show that a combination of innovative formula components, including prebiotics, may play a role in brain development and behavior. In their new study, the team concentrated solely on the effects of prebiotics.

Starting on the second day of life, piglets were given a cow's milk-based infant formula supplemented with polydextrose (PDX), a synthetic carbohydrate with prebiotic activity, and galactooligosaccharide (GOS), a naturally occurring prebiotic. When the piglets were 25 days old, Fleming took them through several learning, memory, and stress tests. After 33 days, blood, brain, and intestinal tissues were collected for analysis.

The test for learning and memory gave a chance to play with dog toys: one they'd seen before and one brand-new toy. If they spent more time with the new toy, that was an indication that the piglet recognized it as new and preferred it. This "novel object recognition" test improves on classic maze tests commonly used in rodent studies.

"If you're trying to test for memory, this test is closer to what we'd do with an infant. After all, we don't generally train infants on mazes," Fleming says. "We know from previous research this test works for pigs, but this is the first published example of using it in a nutrition context."

Pigs fed PDX and GOS spent more time playing with new objects than pigs who didn't receive the prebiotic supplements. The preference for novel objects, an indication of natural curiosity, is a sign of healthy and points towards positive development of learning and memory.

When prebiotics are working the way they should, increase in abundance. One way to tell is by looking at metabolic end-products - volatile fatty acids (VFAs) - excreted by bacteria during digestion of prebiotic fibers.

"Volatile fatty acids are a global indicator for whether prebiotics had an effect on the overall population of bacteria. For example, we might want to see an increase in Lactobacillus and other beneficial bacteria that produce butyrate," Dilger explains. Volatile fatty acid (VFA) concentrations in the colon, blood, and brain were changed in pigs receiving PDX and GOS compared with control pigs.

Recent evidence suggests that bacterial VFAs could be getting into the blood and traveling to the brain, where they could potentially affect mood and behavior.

"We found that, yes, VFAs are absorbed in the blood of pigs that were fed PDX/GOS. And, yes, they do get into the brain," Fleming explains. "But when we looked at the relationship between these VFAs and the results of our behavior tests, there did not appear to be a clear connection."

Another surprise was a decrease in serotonin in brains of pigs fed the . "When you hear less serotonin, there's an immediate reaction to say, 'Well, that's bad,'" Fleming says. Not necessarily; those pigs didn't show greater anxiety than control pigs during a stress test or poorer performance when given a learning and memory . The researchers hypothesize that the prebiotics may alter levels of tryptophan, serotonin's amino acid precursor, but it's too early to say.

Although more work is needed to tackle remaining questions, the study adds to the growing body of research suggesting a strong and potentially modifiable link between the gut and the brain: a link that makers of infant formula should strongly consider.

"There are so many ways we can alter the composition of the microbiota and they can have very strong benefits. Promoting good 'gut health' remains a strong focus in the field of nutrition," Dilger says.

Explore further: Novel combination of ingredients may offer greater support for infant brain development

More information: Stephen A. Fleming et al, Dietary polydextrose and galactooligosaccharide increase exploratory behavior, improve recognition memory, and alter neurochemistry in the young pig, Nutritional Neuroscience (2017). DOI: 10.1080/1028415X.2017.1415280

Related Stories

Novel combination of ingredients may offer greater support for infant brain development

February 18, 2016
Research has shown that nutrition plays an important role in the rapid structural development of the brain during the first few months of life. Scientists at the University of Illinois interested in this connection have studied ...

Study sheds new light on importance of human breast milk ingredient

May 14, 2012
A new University of Illinois study shows that human milk oligosaccharides, or HMO, produce short-chain fatty acids that feed a beneficial microbial population in the infant gut. Not only that, the bacterial composition adjusts ...

Gut microbes may talk to the brain through cortisol

August 21, 2017
Gut microbes have been in the news a lot lately. Recent studies show they can influence human health, behavior, and certain neurological disorders, such as autism. But just how do they communicate with the brain? Results ...

Prebiotics: Do supplements in baby formula help prevent allergies?

March 27, 2013
Prebiotic supplements in infant formula may help to prevent eczema, according to a systematic review published in The Cochrane Library. However, the review highlights a lack of high quality evidence for the effects of prebiotics ...

Recommended for you

Researchers define molecular basis to explain link between a pregnant mother's nutrition and infant growth

May 24, 2018
For years, pregnant mothers have questioned their nutritional habits: "Will eating more cause my baby to be overweight?" Or, "I'm eating for two, so it won't hurt to have an extra serving, right?"

Study suggests brainwave link between disparate disorders

May 24, 2018
A brainwave abnormality could be a common link between Parkinson's disease, neuropathic pain, tinnitus and depression—a link that authors of a new study suggest could lead to treatment for all four conditions.

In a break with dogma, myelin boosts neuron growth in spinal cord injuries

May 23, 2018
Recovery after severe spinal cord injury is notoriously fraught, with permanent paralysis often the result. In recent years, researchers have increasingly turned to stem cell-based therapies as a potential method for repairing ...

Memory molecule limits plasticity by calibrating calcium

May 23, 2018
The brain has an incredible capacity to support a lifetime of learning and memory. Each new experience fundamentally alters the connections between cells in the brain called synapses. To accommodate synaptic alterations, ...

New type of vertigo identified

May 23, 2018
Neurologists have identified a new type of vertigo with no known cause, according to a study published in the May 23, 2018, online issue of Neurology, the medical journal of the American Academy of Neurology.

Study confirms that men and women tend to adopt different navigation strategies

May 23, 2018
When navigating in a known environment, men prefer to take shortcuts to reach their destination more quickly, while women tend to use routes they know. This is according to Alexander Boone of UC Santa Barbara in the US who ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.