Probiotics, dietary fibre intake shown to reduce medicines-induced weight gain – 12-week RCT

The study, said to be the first examining the effects of probiotics and dietary fibre intake on antipsychobiotics-induced weight gain, took place between August 2019 and June 2021.

It was conducted by researchers from the Co-innovation Center of Neuroregeneration at Nantong University and The Second Xiangya Hospital of Central South University in Hunan.

The findings were recently published in Translational Psychiatry. ​

The researchers pointed out that most antipsychotic medications, such as olanzapine for treating symptoms in schizophrenia, can induce weight gain, insulin resistance, and disruptions to the metabolic system.

As such, they conducted the study in four arms to find out whether probiotics with dietary fibre could control antipsychotic medicines-induced weight gain, BMI, and other areas such as insulin levels, lipid profiles, and the changes to the gut microbiome.

The four arms were: 1) probiotics plus dietary fibre, 2) probiotics alone, 3) dietary fibre alone, and 4) placebo. Each group had 34 participants and 83.1 per cent of the participants completed the study.

“In the present study, the effects of attenuating weight gain and metabolic disturbances were more evident in the probiotics plus prebiotics group, suggesting that probiotics and dietary fibre may have synergistic effects on the observed improvements,”​ the researchers said.

The probiotics given was a capsule containing live Lactobacillus, Bifidobacterium,​ and Enterococcus​ bacteria commercially available under the trademark Bifico and sold by Shanghai Xinyi Pharmaceutical.  

Each capsule contains 1.7bn CFU/g of Bifidobacterium​, 380m CFU/g of Lactobacillus​, and 780m CFU/g of Enterococcus​.

The dietary fibre used was a powder drink sold commercially as HI-FIBRE drink plus 20g Extra Herb Powder from Perfect Co, a company based in Zhongshan, China.

The intervention group had to take four capsules of Bifico after breakfast and dinner, which was equivalent to a total daily intake of 1,680mg of probiotics. They also took the dietary fibre supplement powder drink together with the probiotics.

Stool samples were collected from the participants as part of the research.

Weight, BMI reduction ​

Weight and BMI reduced significantly in the group taking both probiotics and dietary fibre, but the opposite was true for the placebo group.

No significant changes were seen in weight and BMI of the groups taking probiotics or dietary fibre.

Specifically, the probiotics plus dietary fibre group saw their weight significantly went down by 2.36kg over the 12-week study, but that of the placebo group had increased by 2.63kg.

The mean BMI of the probiotics plus dietary fibre group also significantly decreased by 0.89 but increased by 1.03 in the placebo group.

Insulin increased, HDL decreased ​

Insulin levels had increased significantly in the placebo group by the end of the study.

At the same time, their levels of high-density lipoprotein (HDL) cholesterol, also known as the ‘good cholesterol’ had decreased.

Specifically, the placebo group had a significantly increased insulin level of 4.61 µIU/mL. while their HDL cholesterol had decreased by 0.12 mmol/L.

In contrast, the probiotics and dietary fibre group saw insulin level reduced by 1.59 µIU/mL, while its HDL cholesterol went up slightly by 0.02 mmol/L.

As for the groups taking probiotics or dietary fibre, their insulin levels had increased by 0.27 and 1.53 µIU/mL respectively.

HDL cholesterol level increased by 0.06 mmol/L in the probiotics only group and remained unchanged in the dietary fibre group.

Gut microbiota changes ​

Gut microbiota diversity in the probiotics plus dietary fibre group had improved by the end of the study, with an increased abundance of Bacteroidetes normally associated with reduction in obesity.

In fact, a greater richness of the gut microbiota was associated with a decrease in weight, the researchers pointed out.

“The increased abundances of Bacteroides thetaiotaomicron, Bacteroides uniformis, and Parabacteroides goldsteinii were observed, which have been reported to decrease in obese individuals and its increase alleviated weight gain and adiposity in mice,”​ they said.

However, they also acknowledged that the number of stool samples collected was of a small sample size, and the preliminary gut microbiota results required further validation.

Only 33 subjects provided stool samples before and after the 12-week RCT, while 62 subjects provided at least one stool sample.

Nonetheless, they concluded that this study showed that the intake of both probiotics and dietary fibre could lead to significant weight loss.

Source:​ Translational Psychiatry​

"The effects of probiotics plus dietary fiber on antipsychotic-induced weight gain: a randomized clinical trial"​

DOI:​ 10.1038/s41398-022-01958-2​

Authors:​ Jing Huang, et al.​