Can transplanting bacteria help you lose weight? The first human trial proves that if you want to lose weight, you can use some slimming bacteria

Recently, the first randomized, double-blind, placebo-controlled phase 2 clinical trial from Canada showed that microbiota-suppressing fiber supplementation from a healthy gut benefits patients with severe obesity and metabolic syndrome.

It is not only effective but also safe. Throughout the entire process, it was safe and well tolerated, with no adverse reactions occurring.

Fecal microbiota transplantation (FMT) is the use of microorganisms from healthy fecal donors to transplant to patients. As introduced in the last section of the course, this technology is currently widely used to treat Clostridium difficile infection, and research is being conducted to test its effectiveness in treating other diseases such as inflammatory bowel disease, mental health and metabolic diseases.

For the study, they recruited 70 severely obese patients, all with a BMI of more than 40, who suffered from metabolic syndrome, insulin resistance, high blood sugar, high blood pressure and other complications that may eventually lead to diabetes.

They were then randomly assigned to receive FMT plus a high-fermentable fiber supplement (HF), FMT plus a low-fermentable fiber supplement (LF), high-fermentable fiber supplement (HF) alone, and low-fermentable fiber supplement (LF) alone.

The fecal microbes in the study came from four healthy, thin people. The preparation process is a bit heavy, so I won’t describe it in detail. However, it is still very convenient to use, and the bacterial powder will be packed in capsules to avoid unacceptable odor.

At the end of the six-week trial, the research team found that only the FMT low-fermentable fiber supplement (LF) group showed significant improvements. These people had better insulin sensitivity and more beneficial intestinal microorganisms, which not only lowered blood sugar but also made their metabolism healthier.

Why is only this group effective?

This is what makes this study special, because this study does not simply move the bacteria over, but fully considers the food of the bacterial flora. It is not a simple immigration, but giving them food at the same time. Fiber supplements after transplantation are the key to success. Think about it, after transplanting beneficial microorganisms, do you still have to feed them? Only in this way can they survive for a long time.

The transplanted bacteria love to eat things that most of the human body cannot digest, such as dietary fiber. However, if the transplanted bacteria continue to eat processed foods without dietary fiber supplementation, these microorganisms may die soon.

The research team also experimented with fermentable fiber (which is more abundant in beans) and non-fermentable fiber (mainly cellulose, which is more abundant in whole grains), and the results showed that non-fermentable fiber was more effective.

The research team believes that non-fermentable fiber can change intestinal motility, act as a bulking agent and binder, and alter bile acid levels, which may explain its role in treatment.

This research once again proves that the potential for using gut microbes to improve human health is huge, but we are only just scratching the surface.

This study also reminds us once again that eating less processed foods and more fiber-containing foods (such as whole grains, fruits and vegetables) is beneficial to the health of our gut microbiome.

Mocanu, V., Zhang, Z., Deehan, EC et al. Fecal microbial transplantation and fiber supplementation in patients with severe obesity and metabolic syndrome: a randomized double-blind, placebo-controlled phase 2 trial. Nat Med (2021). https://doi.org/10.1038/s41591-021-01399-2