Specifically, the researchers were able to decrease ratios of the bacteria Firmicutes and Bacteroidetes—of which an increased level is associated with organisms who eat high fat diets—in the rats’ feces, among other outcomes.
Their report, available online, is due for publication in the October issued of the journal Nutrition.
The team of researchers from Chiang Mai University in Thailand looked at the potential benefits of probiotic strain Lactobacillus paracasei HII01 as an intervention for obesity-related ailments. The strain comes from Thai pickled leeks and red shallots, listed in the Thailand Institute of Scientific and Technological Research microbial culture collection.
The team previously published a study on the strain’s potential cognitive function benefits, which was published earlier this year in the Journal of Neuroinflammation.
“In this study…we hypothesized that the long-term consumption of probiotic L. paracasei HII01 and prebiotic xylooligosaccharide (XOS) with the additive benefit of their synbiotic effect would improve metabolic parameters in obese-insulin resistant rats,” they wrote.
Their conclusion was that supplementation in obese rats corrected their ‘gut dysbiosis,’ a term some researchers use to describe gut microbiota composition that has shifted from the host’s norm.
The researchers studied 30 rats, 24 of them fed a high fat diet (where 60% of the energy came from fat) while six rats were fed a normal diet (with 20% of energy from fat).
At week 13, high-fat diet rats were further divided into four groups with six rats per group. These rats were fed either just the probiotic (1 mL of 1 x 108 CFU L. paracasei HII01), just the prebiotic (1 mL of 10% XOS), a combination of the two with the same amounts and dosage, or phosphate buffered saline as a placebo.
Supplementation was given using oral gavage for 12 weeks.
Outcomes and implications
The authors reported that inducing obesity using a high-fat diet altered the microbiome (bacterial composition) of the rats’ feces and created insulin resistance.
Additionally, they found that rats that were supplemented with the probiotic, prebiotic, and the combination expressed “significantly improved insulin sensitivity that was initiated by the high-fat diet as indicated by decreased plasma insulin.”
This trend was not seen in the two other groups of rats (normal diet and placebo-supplemented rats).
This led the researchers to conclude that “the daily consumption of probiotic L. paracasei HII01, prebiotic XOS, and [the combination] reduced metabolic disturbances in obese-insulin resistant rats.”
The underlying mechanism is still unclear, but the authors postulated that potential benefits could be due to the inhibition of gut dysbiosis by lowering the population of lipopolysaccharide-containing Enterobacteriaceae within the gut.
Published online ahead of print, https://doi.org/10.1016/j.nut.2018.03.005
Lactobacillus paracasei HII01, xylooligosaccharides, and synbiotics reduce gut disturbance in obese rats
Authors: Parameth Thiennimitr, et al