Can I lose weight by manipulating the gut microbiome?
In terms of treating the gut microbiota to lose weight, long-term human trials are needed before we can make any extravagant claims, but there is still a lot to go one from the available data on probiotics, prebiotics, diet, and other ways of altering the gut microbiota. Here’s what some of the studies show:
Fermented kimchi reduces body weight and improves metabolic parameters in overweight and obese patients (40).
A recent review of 61 studies show that prebiotics and probiotics usually promote increases in bifidobacteria, weight loss, and enhancement of parameters related to obesity (41).
Anti-obesity effects of gut microbiota are associated with lactic acid bacteria (42,43,44).
Supplementing with prebiotics such as oligofructose has the potential to promote weight loss and improve glucose regulation in overweight adults (45,46,47).
However, not all studies find an association between probiotic consumption and changes in body weight, and the primary problem seems to be that a lot of the clinical trials investigate the effects of a single probiotic supplement on inflammation, glucose tolerance, and weight loss. Since we know that the gut microbiota consists of hundreds of species of bacteria and that probiotics often lack the ability to colonize the gut, just ingesting a handful of species of lactic acid bacteria from a supplement will usually have little impact on body weight. We also know that only some species of bacteria seem to be effective and that a lot of the probiotic supplements on the market don’t contain the quantity of colony-forming units claimed on the label.
This doesn’t mean that all probiotics are a waste of money, as some strains of probiotics have been shown to increase the number of beneficial bacteria in the gut and promote a more diverse microbiota (48,49).
The same principles apply for the typical store-bought yogurt – It contains only a handful of species of bacteria that won’t have any long-lasting impact on the gut microbiota.
The human microbiome is one of the hottest research subjects in the scientific community at the moment, and we’re slowly learning more and more about the complex interaction between microbes and the human host. This has also led to increased interest from the corporate health industry, and some companies have already begun financing the production of advanced “microbiome modulators“. It’s possible that we’ll soon see a whole new spectrum of probiotics and drugs that are directed at the trillions of microbes that inhabit the human body. Could the microbes that live in and on our bodies be one of the biggest blind spots in the history of medicine?
Just taking a probiotic supplement or eating some yogurt from the supermarket will have little, if any, benefit. Rather it seems that a diet that contains nutrient-rich whole foods, prebiotic fiber such as resistant starch and oligofructose, and traditionally fermented foods such as sauerkraut, kimchi, and kefir is optimal for people who want a healthy and diverse gut microbiome.
There are also several other factors besides diet that impact the microbiome, such as antibiotics, c-section vs. natural birth, and breastfeeding vs. bottle feeding. It also seems that modern hygiene often is to the detriment of our microbiome, and that triple-washing organic produce from the garden or farmer’s market probably isn’t a good idea if you want to increase bacterial diversity (50).
Liberation from self
The primary takeaway is that we have to stop looking at the human body as a single organism, and rather acknowledge that diet and lifestyle have to be tailored to a complex ecosystem made up of trillions of microbes living symbiotically with the human host. We also have to realize that the microbes that inhabit our body are passed on to the children we bring to life through birth, breastfeeding, and other types of close contact. It’s therefore highly likely that part of the genetic component of obesity and other health disorders has to do with transferring microbes and their DNA onto the child.
It’s also important to note that although this article has focused on the role microbes play in overweight and obesity, we are now learning that the microbiome has an essential role in both our mental and physiological health, and it’s therefore no doubt that paying attention to the old friends that inhabit your body is important even if you are perfectly happy with your physical appearance.
Going back to the quote from Albert Einstein, it’s clear that the expanding view on the human body is one that certainly leads to liberation from self.