Does fasting improve gut health? What to know
IIf you spend a lot of time online, you may have noticed that parts of the Internet have started to go viral fast. Online message boards are flooded with posts promoting the benefits of time-restricted eating and intermittent fasting method involves not eating food or drinks with calories for an extended period of time — anywhere from 12 hours to several days. These online testimonials have helped popularize intermittent fasting, and they often feature two common rationalizations: One, humans evolved in an environment of food scarcity, and meals took place without frequent; and second, the relatively recent switch to intermittent fasting has taken a toll on our gut and metabolic health.
Harness the internet for accurate information, especially when it comes to Diet, can feel like gold. You have to sift through a lot of junk to find anything of value. But this is a case where nuggets can be easily found. Lots of published peer-reviewed studies on intermittent fasting make the same claims you’ll find on those Reddit message boards. The authors of a 2021 review article wrote in American Journal of Physiology. “Knowledge of early human evolution and data from recent studies of hunter-gatherer societies suggest that humans evolved in environments with alternating periods of food scarcity.” They said fasting mode may provide a period of “gut rest” that may lead to a number of significant health benefits, including improved gut microbiota diversity, gut barrier function, and gut function. immunity.
The past decade has seen an explosion in fasting-related research. (According to Google Scholar, there have been nearly 150,000 articles examining or addressing fasting in the past five years alone.) While that work helped establish the link between intermittent fasting and weight loss, it also like other benefits, but it’s not clear when (or if) fasting can help with gut disease. “I would still consider the evidence to be moderate,” said Dr. Emeran Mayer, professor of medicine and founding director of the Goodman Luskin Microbiome Center at the University of California, Los Angeles. “[Fasting] It looks like a prudent way to maintain metabolic health or re-establish metabolic health, but it is not a miracle cure.”
When it comes to gut conditions like inflammatory bowel disease (IBD), he said that the study was either absent or fruitless. In their view, the researchers have found that fasting Ramadan – a month-long religious period when people don’t eat or drink between sunrise and sunset – has essentially able to “repair” the gut microbial community in useful and healthy ways. However, in people with IBD, studies of fasting Ramadan have also found that a person’s intestinal symptoms may worsen.
While it’s too early to recommend a fasting plan as a panacea for gut-related disorders, experts say there’s still reason to hope these approaches could emerge. present as a form of treatment. It is clear that some radical, and perhaps entirely beneficial, things happen when you give your body a break.
How fasting can repair the intestines
For a series of recent studies, a team of researchers based in the Netherlands and China looked at the impact of Ramadan style intermittent fasting on the gut microbiome — the billions of bacteria that inhabit the human gastrointestinal tract. (The month of Ramadan pops up a lot in published studies because it offers a real-time opportunity for experts to examine the effects of a 12- or 16-hour fast, which is something that many cockroach diets don’t do.) popular passage.) “We really wanted to know what Dr. Maikel Peppelenbosch, a member of the research team and professor of gastroenterology at Erasmus University Medical Center, the Netherlands. “Overall, we have seen that intermittent fasting very clearly changes the microbiome and we view some of the changes as beneficial. If you look at fasting in general, not just Ramadan, you see certain types of bacteria on the rise.”
For example, he says that intermittent fasting increases the gut population of a family of bacteria known as Family Lachnospiraceae. “In the gut, bacteria are constantly fighting for ecological space,” he explains. Unlike some other gut microorganisms, Family Lachnospiraceae can happily exist in an empty digestive tract. “They can live off of the slime that the gut makes on its own, so they can compete with other bacteria in a fasted state.” Family Lachnospiraceae produces a short-chain fatty acid called butyrate, which seems to be important for gut health. Butyrate sends anti-inflammatory signals to the immune system, which may help reduce pain and other symptoms of intestinal dysfunction. Butyrate also improves the barrier function of the gut, says Peppelenbosch. This is, potentially, a huge problem. Poor barrier function (sometimes referred to as “leaky gut”) is a telltale sign of common digestive conditions, including inflammatory bowel disease. If intermittent fasting can reduce inflammation and also help normalize the walls of the digestive tract, those changes could have major therapeutic implications.
Family Lachnospiraceae just one of many helpful bacteria that research has linked to a fasting plan. But up to this point, there are still a lot of holes in the science. Peppelenbosch says that the intestines of people with intestinal disorders do not seem to respond to fasting in exactly the same way as the intestines of people without these health problems. “In sick people, we see similar changes to the microbiome, but it’s not as obvious as in healthy volunteers,” he said. “So we’re now really trying to figure out what’s going on there.”
A shift in healthy microbiome isn’t the only benefit that researchers have associated with intermittent fasting. UCLA’s Mayer refers to a phenomenon known as the migrating motor complex. “This is rarely mentioned in fasting papers these days, but when I was a junior instructor it was one of the hottest discoveries in digestive research,” he says. The migrating motor complex refers to repeated cycles of powerful contractions that sweep intestinal substances, including bacteria, down the colon. “It’s this 90-minute wave of repetitive contractions that rush down the intestines, and its power is comparable to a nutcracker,” he said. Basically, this motorcycle complex works like a street cleaning crew cleaning up after a parade. It ensures bowels are flushed out and cleaned between meals, through the 90-minute repetition cycle that fasting allows to become more frequent. It also helps to rebalance the gut microbiota so that more of them reside in the colon and lower areas of the digestive tract. “But it stopped as soon as you took a bite – it went off immediately,” he said.
Mayer says that modern eating habits — called “herbivorous” or regular eating throughout the day — leave very little time for the motor complex to move around to do its job. “This function is eliminated over time as we sleep, but even this is disrupted because many people wake up in the middle of the night and snack on something,” he said. “So the longer periods of when we’ve re-cleaned and rebalanced our gut so we have a normal distribution of bacteria and a normal population density – have been severely disturbed. by these lifestyle changes.”
Ideally, Mayer says, people can (mostly) stick to the type of time-restricted eating program that allows a full 12 to 14 hours a day for the exercise complex to work. “If you don’t snack, this motor complex happens between meals, and you’ll also get this 12- to 14-hour period at night when the digestive system is empty,” he explains. In other words, eating three meals a day and avoiding snacking between meals (or snacks at night) should be enough. But again, it remains unclear whether this eating schedule can reverse intestinal damage or treat existing dysfunctions.
Read more: The truth about fasting and type 2 diabetes
More potential benefits
Another benefit of fasting involves a biological process known as “autophagy”. During autophagy, old or damaged cells die and are eliminated by the body. Some researchers have called it a helpful housecleaning mechanism, and it occurs naturally when the body is without energy (calories) for a long time. There is some expert speculation, mainly based on evidence in animal and laboratory studies, that autophagy may help promote gut health or combat these types of barrier problems in people with IBD. But these improvements have yet to be demonstrated in actual clinical trials involving humans.
Meanwhile, some experts have found that fasting can help re-align the gut’s metabolic rhythm in helpful ways. “By changing the timing of the diet, this will actually change the activity of the
Dr Eran Elinav, principal investigator of the Host Microbial Interaction Research Group at the Weizmann Institute of Science in Israel, said.
Some of Elinav’s work, including an influential 2016 article in the journal Cell, have shown that the gut microbiota undergoes day- and night-time variability that is influenced by a person’s dietary schedule and leads to altered patterns of metabolite production, gene expression, and other factors. another important factor of gut health. “If you change the timing of your diet, you can alter the biological activity of the microbiome,” he said. This could have health implications, though exactly what remains murky.
Read more: What we know about leaky gut syndrome
Fasting won’t get you anywhere
It’s clear that when you eat, including how often you eat, is important for your gut health. But the devil in the details. At this time, it is not clear how intermittent fasting can be used to help people with intestinal disorders or metabolic diseases.
“For a condition like IBD, it’s important to distinguish between what you do during a flare and what you do to prevent the next flare-up,” Mayer points out. Research on people observing the month of Ramadan shows that, at least during flare-ups, fasting can make a person’s IBD symptoms worse. Figuring out whether fasting can lead to more lasting improvements is just one of many questions that need to be answered.
While many are still unknown, experts say that popular fasting methods appear to be safe for most people. For example, time-restricted eating involves cramming all of your day’s calories into a single eating window that lasts six to eight hours. Even for people with metabolic diseases like Type 2 diabetes, research shows that this form of fasting is safe, as long as a person is not taking blood sugar-raising medications.
That said, there simply isn’t much benefit from intermittent fasting as a treatment for gut problems. Additionally, there is little research on more extreme forms of fasting, such as plans that involve intermittent fasting without calories for several days. These diets can be curative but can also turn out to be dangerous. If you’re considering any of these methods, talk to your healthcare provider first.
“We really need more and better studies to compare all the different fasting procedures,” says Peppelenbosch. “But in general, increasing the gap between calories consumed is a good thing for you. The body was not made to eat all day. “
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