Chinese researchers discovered that the regimen increased levels of the beneficial Lactobacillus species in the gut along with an anti-inflammatory effect.
“Our findings provide evidence that a TSD may ameliorate fat accumulation by increasing the proportion of the Lactobacillus genus,” the study states.
“Correspondingly, a TSD improved the bioprocess of lipid metabolism and exerted anti-inflammatory effects.
“Thus, not only were metabolic pathways of water-soluble vitamins and cofactors, carbohydrates, vitamins and cofactors modulated, but also the levels of some inflammatory cytokines including IL-17 and MIP-1α were markedly decreased,” the research team adds.
Writing in the journal Current Research in Food Science, the team from Zhejiang University School of Medicine in China, used a TSD to transition from a high-fat diet (HFD) to a Mediterranean diet (MD) avoiding major systemic changes as a result.
Here, 80 mice were randomly divided into eight groups, labelled A to H. The mice in groups A to G were fed an HFD diet for a total of four weeks, and those in group H were fed standard diet.
Meanwhile, a probiotic suspension of Bifidobacterium longum subsp. Longum (ATCC 15707) at a concentration of 1 × 108 colony forming units per millilitre (CFU/ml) was administered to each mouse in groups D and F at 0.2 millilitre (ml) per day for seven days.
After the establishment of the obese model, the diet of the groups A, B, C were switched to chow, HFD and MD respectively.
In order to study the TSD, group E was fed chow for one week and then changed to MD for next week. For the purpose of studying probiotic, groups D and F was given B. longum at week five.
Results revealed that by measuring multiple systemic alterations such as weight, liver function, and histopathology, the team found that an MD, TSD and Bifidobacterium longum all contribute to alleviating lipid accumulation and liver injury.
The downregulation of IL-17 and MIP-1α proteins that promote inflammation and also demonstrated the anti-inflammatory effects of the TSD.
The team also found that the TSD increased the abundance of the Lactobacillus genus and effectively lowered lipid accumulation and systemic inflammation.
Suggested mechanisms of action
“Here, we report that the livers and intestines of mice get improved to some extent after administration of a TSD,” the team writes.
“Lactobacillus augments intestinal barrier function by overproducing mucus, secretory immunoglobulin A (sIgA) and antimicrobial peptides, as well as strengthening tight junctions.”
Combined with the outcomes from liver transcriptome analyses, energy expenditure-related pathways were found to be relatively highly expressed in the TSD groups.
Further findings identified B. longum’s role in the synergistic effect as the researchers suggest that a TSD, “might be useful for HFD-induced obesity before drastic dietary changes, and probiotics were also beneficial.”
“Evidence shows that B. longum has beneficial regulatory effects on host metabolism. Dietary factors may act synergistically with probiotic application in this process, but further studies are needed to elucidate the underlying mechanisms,” the paper adds.
“Overall, the changed metabolic signature indicates that the combination exerted significant effects on the metabolic patterns, which may be achieved by modulating the gut microbiota.”
Source: Current Research in Food Science
Published online: doi.org/10.1016/j.crfs.2023.100435
“Multi-omics analysis of the effects of dietary changes and probiotics on diet-induced obesity”
Authors: Shiman Jiang et al.