Fatty Meal Obstructs Gut's Communication with the Body: Study

If that second helping of prime rib stuns your gut into silence, is that good or bad? Consuming high-fat meals can silence communication between the intestine and the rest of the body, according to a new study.

Gut cells that normally tell the brain and the rest of the body what's going on after a meal shut down completely for a few hours after a high-fat meal. Enteroendocrine cells (EEC) normally produce at least 15 different hormones to send signals to the rest of the body. The finding may be a clue to insulin resistance that leads to Type 2 diabetes. The findings of the study are published in the journal eLife.//

High-fat meal altered gut microbiota composition, sufficient to induce enteroendocrine cells silencing. These results establish a new mechanism by which dietary fat and gut microbiota modulate EEC nutrient sensing and signaling, reports a new study. While using the fish to examine cells that normally tell the brain and the rest of the body what's going on inside the gut after a meal, a team of Duke researchers discovered that a high-fat meal completely shuts down that communication for a few hours.

Red Wine Improves Your Gut Health
Do you wanna choose an alcoholic drink today? Then, opt for red wine because it exerts a beneficial effect on you and your gut microbes. Also, red wine helps in weight loss and reduces the risk of heart disease. However, it is advised to consume in moderation.

‘Consuming high-fat meals can silence communication between the intestine and the rest of the body.’

The cells they were looking at are the enteroendocrine cells, which occur sparsely throughout the lining of the gut, but play a key role in signaling the body about the all-important alimentary canal. In addition to releasing hormones, the cells also have a recently-discovered direct connection to the nervous system and the brain.

These cells produce at least 15 different hormones to send signals to the rest of the body about gut movement, feelings of fullness, digestion, nutrient absorption, insulin sensitivity, and energy storage.

"But they fall asleep on the job for a few hours after a high-fat meal, and we don't yet know if that's good or bad," said John Rawls, an associate professor of molecular genetics and microbiology in the Duke School of Medicine.

Probiotics Help Repair Gut Health After a Junk Meal
The probiotic medicine was able to significantly impact microbial composition in the gut and prevent memory loss after taking junk food.

Since enteroendocrine cells are key players in digestion, the feeling of being full and subsequent feeding behavior, this silencing may be a mechanism that somehow causes people eating a high-fat diet to eat even more.

"This is a previously unappreciated part of the postprandial (after-meal) cycle," Rawls said. "If this happens every time we eat an unhealthy, high-fat meal, it might cause a change in insulin signaling, which could, in turn, contribute to the development of insulin resistance and Type 2 diabetes."

Grapefruit Flavonoid - Inulin Combo in a Western-Type Diet Does Not Improve Gut Health
Grapefruit flavonoid extract with inulin in a Western-type diet does not provide synergistic effects to either the colon health or the blood lipid profile.

To understand the silencing better, the researchers tried to break the process down step by step in zebrafish.

After they first sense a meal, the enteroendocrine cells trigger a calcium burst within seconds, initiating the signaling process. But after that initial signal, there's a delayed effect later in the after-meal period. It's during this later response that the silencing occurs, said Rawls, who also directs Duke's Microbiome Center.

Health Benefits of Probiotic Yogurt Diet
Probiotic yogurt adds bountiful of beneficial bacteria to the intestinal tract which prove to be effective in aiding digestive problems.

The silenced cells change shape and experience stress in their endoplasmic reticulum, a structure that assembles new proteins. It seems that these enteroendocrine cells, which are specialized to synthesize and secrete proteins like hormones and neurotransmitters, become overstimulated and exhausted for a while.

The team tried the high-fat diet on a line of germ-free zebrafish raised in the absence of any microbes and found they didn't experience the same silencing effect. So they began looking for gut microbes that might be involved in the process.

After screening through all the kinds of bacteria found in the gut, they saw that the silencing appeared to be the work of a single type of gut bacteria, called Acinetobacter. These bugs are normally less than 0.1 percent of the total gut microbiome, but they increased 100-fold after a high-fat meal and were the only bacteria able to induce the silencing effect.

"Next, we want to understand how Acinetobacter evokes this interesting response," said Lihua Ye, a postdoctoral fellow and lead author on this paper. "We also suspect other bacteria might also have this capability."

Rawls said they aren't sure why silencing occurs, nor whether it has any positive effect on the fish. It might be a way to prevent excessive signaling about the fat, but by being silenced completely like this, the cells won't be communicating anything else either.

"We don't understand yet what the long-term impact of enteroendocrine silencing would be on metabolic health," Rawls said. "This may be a maladaptive response to high-fat feeding that impairs the normal regulatory functions of these cells, leading to metabolic disorders like insulin resistance. But it's also possible that the silencing is a beneficial adaptation to protect the animal from over-stimulation of the gut cells."

Source-Eurekalert