〇Your insides are full of life. Trillions of bacteria, viruses and fungi call our gastrointestinal metropolis home. Single-celled microbes help break down complex carbohydrates and build vitamins. They patrol dark back alleys to keep nasty pathogens at bay. They send signals across our intestinal pathways.Scientists have been investigating these microbial citizens for decades. Unlocking its secrets could help us understand, prevent, and treat diseases from heart disease to Alzheimer’s.
As half of all Americans will be clinically obese by 2030, weight loss applications may be at the forefront of gut microbiome research. In 2013, Lee Kaplan and Jeffrey Gordon, gastroenterologists at Massachusetts General Hospital (my home institution) and Washington University School of Medicine in St. Louis, respectively, conducted separate studies to demonstrate this possibility. In a Kaplan study published in Science Translational Medicinemice that underwent weight-loss surgery exhibited marked changes in their gut microbiota. Fecal microbiota transplantation (FMT) allowed Kaplan to achieve 20% of the benefits of weight loss surgery without surgery (5:178ra41).
Obesity may decline in the absence of more targeted strategies. You need a scalpel, not a sledgehammer.
In Gordon’s research published in chemistry, mice received feces from obese and non-obese twins.Mice fed the faeces of the lean twins remained lean, while mice fed the faeces of the obese twins gained weight. By allowing them to eat (which, in fact, is what mice do), overweight mice were able to lose weight, as long as they were all fed a low-fat diet (341:1241214). The step of Gordon said new york timeswas to determine which gut bacterial species induced leanness in order to give patients specific microbes as a treatment for obesity.
Fast forward 10 years and we’ve moved on to human-to-human FMT experiments. Mass General Endocrinologist Elaine Yu and Brigham and Women’s Hospital gastroenterologist Jessica Allegretti are conducting separate clinical trials in so-called “blind” FMT. In other words, they are looking to see if oral capsules containing lean donor feces (or Crapsul, if you will) help obese patients lose weight. Preliminary results published several years ago from both trials showed no significant change in body weight. Without more targeted strategies, hopes for microbial-based therapies for obesity may fade. You need a scalpel, not a sledgehammer.
Nonetheless, these sobering findings have done little to stem the hype surrounding FMT and microbial therapy more broadly. It raised about $130 million on its first day of going public in March 2021, promising a freeze-dried poop pill that would treat everything from Crohn’s disease to obesity. However, the company does not yet have a product on the market. Similarly, microbiome researcher Jeff Leach made national news coverage by using a turkey baster to sprinkle his FMT, a do-it-yourself faeces from the Hadza people of Tanzania, into his gut. Earned. (He earned the nickname “Doctor Shit” in Swahili.) Leach is the presumably morbid and industrialized man whose studies have been linked to obesity, diabetes, and other chronic diseases. He was trying to “rewild” his gut microbiome from a tainted state. Allegedly healthier, ancestral. Many companies in the weight loss supplement industry, estimated at $94.5 billion in 2022, have also jumped on the bandwagon, pitching questionable weight loss claims about prebiotics and probiotics.
Perhaps what explains the irrepressible excitement surrounding microbial treatments for obesity is that the solutions seem simple. will be The condition is commonly conceptualized as a lifestyle disease caused by bad behavior. So, rather than resorting to seemingly extreme medications or weight loss surgery, more “natural” options such as taking poop pills have a certain appeal. For example, in at least one case, a person developed obesity after receiving FMT to treat a relapse. Clostridium difficile Infections for which FMT is the standard of care. Therefore, altering the gut microbiome in the name of weight loss alone may not be safe or feasible. What new problems might this short-sighted focus create?
Maybe we’ll eventually figure out how to shape our gut microbiome to target obesity. There’s obvious reason to be optimistic, but there’s still not enough evidence to justify all the hype.Obesity is a complex chronic disease that is influenced by the gut microbiome, but not necessarily a disease. of intestinal microbiota. Therefore, treatment of obesity requires diverse solutions. After centuries of trying to pin the problem down to her one culprit and identify a simple cure, there’s no silver bullet.
Simar Bajaj He is a research fellow at Massachusetts General Hospital and Stanford University School of Medicine, studying obesity and cardiothoracic surgery.
