FMT not tied to pre or post surgical weight loss in obese patients undergoing Bariatric surgery: JAMA

Finland: A study has concluded that Fecal microbiota transplantation (FMT) by gastroscopy into the duodenum has no relation with the body weight of obese participants.

This original investigation in Gastroenterology and Hepatology was published in the JAMA network.

It is already known that severe obesity is one of the significant health concerns. The most effective treatment strategy is obesity surgery.

Bariatric surgery has been shown to reduce mortality and improve quality of life (QoL) in such patients. The patients achieve minimal weight reduction after bariatric surgery or regain weight after some time.

Fecal microbiota transplantation (FMT) treats obesity in mouse models. The results have mentioned slightly improved insulin sensitivity, abdominal adiposity and lipid metabolism.

There has to be more data on its effect on body weight. Most obese patients harbor an intestinal microbiota with decreased bacterial diversity and microbial gene richness than healthy controls. The microbial gene richness is improved by bariatric surgery.

Considering this, a study was conducted by a team of researchers to investigate,

Does Fecal Microbiota Transplantation (FMT) from a lean donor reduce body weight and improve bariatric surgery results further?

Does enriching intestinal microbiota with FMT improve bariatric surgery outcomes?

The lead researcher was Dr Perttu Lahtinen, MD, from the Department of Gastroenterology, Päijät-Häme Central Hospital, Lahti, Finland.

The study points are:

• Adults with severe obesity and obesity-related comorbidity were included in the study.
• The study participant's mean age was 48.7 years.
• There were 12 men and 29 women in the study.
• The location/settings of the study were two hospitals in Finland.
• The intervention included the administration of FMT from a lean donor or the patient (autologous placebo) by gastroscopy into the duodenum. Six months after the baseline intervention, Bariatric surgery was performed using LRYGB (laparoscopic Roux-en-Y gastric bypass) or LSG (laparoscopic sleeve gastrectomy).
• The weight reduction (total weight loss percentage) was the primary outcome measured.
• Forty-one patients were randomized.
• The mean body mass index was 42.5
• 21 patients received FMT from a lean donor.
• 20 patients were given an autologous placebo.
• 34 patients underwent LRYGB, and 4 underwent LSG (Six months after FMT).
• Thirty-four patients constituting 82.9%, attended the last visit 18 months after the baseline visit.
• There was no statistically significant difference in total weight loss percentage between the groups at six months and 18 months following the intervention.
• TWL percentage at six months in FMT and placebo was 4.8% and 4.6%.
• No difference was reported between the groups.
• At 18 months from the baseline, TWL percentage in FMT and placebo was 25.3% and 25.2%. No difference was reported between the groups.
• Between-group difference in TWL at six months from baseline intervention absolute difference was 0.2 %, and at 18 months from baseline intervention absolute difference was 0.1 %.

The researchers said,

"The presurgical and postsurgical weight loss is not affected by FMT. Further studies are required to elucidate the FMT role in obesity"

Further reading:

Lahtinen P, Juuti A, Luostarinen M, et al. Effectiveness of Fecal Microbiota Transplantation for Weight Loss in Patients With Obesity Undergoing Bariatric Surgery: A Randomized Clinical Trial. JAMA Netw Open. 2022;5(12):e2247226. doi:10.1001/jamanetworkopen.2022.47226