What is the Gut trying to tell Us
Posted by Kelli de Sante' on 27th Jun 2021
What is the gut trying to tell us?
Scientists are exploring how and why microbes communicate with the brain to tell us what nutrients we are lacking. 1*
You’ve heard the expression, what is your heart leading you to do? Well, there is another part of your body trying to send you key messages. So the question is, “what is your gut leading you to do?” While what we put in our mouths alters our gut bacteria which ultimately can influence how we feel, how healthy we are, and what foods we will crave in the future, the gut bacteria also communicate with the brain to tell us what foods we should be putting into our bodies.
When we eat a lot of sugar, processed food, and heavy greasy foods, we usually don’t feel great. We feel bloated, tired and it can even make us feel depressed and lethargic. Too much sugar can cause crankiness. Have you ever witnessed a kid have a breakdown after eating too much sugar? This happens because what we eat can alter the balance of bacteria in the gut, and that balance can alter how we feel. When you choose to eat vegetables versus a candy bar, you can either boost the number of friendly microbes by feeding them or decrease them. When the number of friendly bacteria changes, “…they secrete different substances, activate different genes and absorb different nutrients…”. Gut microbes can also influence diet and behavior as well as anxiety, depression, hypertension, and a variety of other conditions. 1*
And those food choices are a two-way street. Our bodies, if we listen to them, will tell us what we should eat as well. In some cases, it can trick us into thinking we need sugar. What happens when the balance of bad bacteria to good bacteria is out of whack in our guts and those dominant bacteria are known as candida Albicans causes us to crave sugar. But our bodies are also very good at telling us what we are lacking. When we are not getting enough of certain nutrients and vitamins, we might actually crave certain foods that will help balance out our health. For example, a pregnant woman might crave orange juice which is full of folic acid, which is important during pregnancy…or when you are sick, sugar and alcohol just don’t sound good while fresh fruit and chicken broth do. 1*
While scientists have known that the microbiome influences our decisions on which foods we choose, how it does this has been a mystery. That’s where a group of neuroscientists from the Champalimaud Center for the Unknown in Lisbon. enters the picture. Through their research, they have revealed that specific types of gut bacteria help a host detect which nutrients are missing in their diets and then ascertain how much of those nutrients the host really needs to eat. Essentially, the bacteria regulate deficiencies and signal the brain when it needs to add more nutrients to the body to keep it working efficiently. The senior author Carlos Ribeiro was able to identify this by studying the eating behaviors of Drosophila melanogaster, a type of fruit fly.
The paper, which was published recently in PLOS Biology by Ribeiro and his team demonstrated how the microbiome influences this fruit fly’s nutritional decisions. “…First, they fed one group of flies a sucrose solution containing all the necessary amino acids. Another group got a mix that had some of the amino acids needed to make protein but lacked essential amino acids that the host cannot create by itself. For the third group of flies, the scientists removed essential amino acids from the food one by one to determine which was being detected by the microbiome…”1*
The results were fascinating. “…After 72 hours on the various diets, flies in all three groups were presented with a buffet offering their usual sugary solution alongside protein-rich yeast. The researchers found that flies in the two groups whose diet lacked any single essential amino acid got a strong craving for yeast to make up for the missing nutrients. But when scientists increased five different types of bacteria found in the flies’ digestive tracts—Lactobacillus Plantarum, L. Brevis, Acetobacter pomorum, Commensalibacter intestine, and Enterococcus faecalis—the flies completely lost the urge to eat more protein…”1*
The researchers found that the bacteria were not simply replacing missing nutrients from the flies’ diet, as the. flies’ amino acid levels were still low which told them they weren’t producing the amino acids themselves. Instead, the microbes were metabolizing the food they got into new chemicals, signaling the host animal it could go on without the amino acids. This “microbial trick” allowed the flies to continue reproducing despite an amino acid deficiency that usually hampers cell growth and regeneration. 1*
There were two kinds of bacteria, Lactobacillus and Acetobacter that had an effect on the flies’ appetites. By increasing both bacteria types, it suppressed the flies’ cravings for protein and increased their appetite for sugar. They also restored their ability to reproduce, which indicated that their bodies were able to carry out normal functions…the ones that usually are restricted when a nutritional deficiency is present.1*
The following step involved removing an enzyme that the flies needed to process the amino acid tyrosine. This made it necessary for the flies to get tyrosine from their food, as is the case with other essential amino acids. In the modified flies, Lactobacillus and Acetobacter did not suppress their cravings for tyrosine. “…“This shows that the gut microbiome has evolved to titrate only the normal essential amino acid intake,”…” Ribeiro explains.1*
According to Jane Foster, a neuroscientist at McMaster University in Ontario and not associated with the study, the research offers a different view of the coevolution of microbes and their hosts. “…“The findings show there is a unique pathway that has coevolved between animals and the resident bacteria in their gut, and there is a bottom-up communication about diet.”…” 1*
This study provides good evidence that “…microbially derived metabolites carry information from the gut to the brain, telling the host whether it needs a particular kind of food..”1*
Over time, we have lost the ability to produce essential amino acids, and this study is seeking to help understand why. Ribeiro offers that “… “Maybe these metabolites gave animals more leeway to be independent of these nutrients and to deal without them sometimes.”…”1*
Microbes feed on what we eat, and without a host, they can’t populate, so they may have had their own “…evolutionary reasons for communicating with the brain….” As with so many studies, the research and data are limited to animal models, but will ultimately help improve behaviors related to diet in the future.1*
We know the gut communicates with the brain. Listening to what it tells you is important for stellar health. But what happens when it tells us to eat sugar and we can’t ward off those cravings? What does that mean? We will cover this next time.
Healthiest wishes,
Kelli
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