here is a study that was sent in to me by one of the vets on here zaccass
https://www.frontiersin.org/articles/10.3389/fcimb.2023.1269548/full
this study showed the following:
Objective: Intermittent energy restriction (IER) is an effective weight loss strategy. However, little is known about the dynamic effects of IER on the brain-gut-microbiome axis.
Methods: In this study, a total of 25 obese individuals successfully lost weight after a 2-month IER intervention. FMRI was used to determine the activity of brain regions. Metagenomic sequencing was performed to identify differentially abundant gut microbes and pathways in from fecal samples.
Results: Our results showed that IER longitudinally reduced the activity of obese-related brain regions at different timepoints, including the inferior frontal orbital gyrus in the cognitive control circuit, the putamen in the emotion and learning circuit, and the anterior cingulate cortex in the sensory circuit. IER longitudinally reduced E. coli abundance across multiple timepoints while elevating the abundance of obesity-related Faecalibacterium prausnitzii, Parabacteroides distasonis, and Bacterokles uniformis. Correlation analysis revealed longitudinally correlations between gut bacteria abundance alterations and brain activity changes.
Conclusions: There was dynamical alteration of BGM axis (the communication of E. coli with specific brain regions) during the weight loss under the IER.
In the study, each participant underwent two dietary phases: a "high-controlled" fasting phase and a "low-controlled" fasting phase.
During the high-controlled phase, participants spent 32 days receiving meals from dietitians that slowly decreased in calorie count down to around one-quarter of their basic energy needs.
For 30 more days after this, they underwent the low-controlled fasting phase, where they were given a list of recommended foods designed to give the women only 500 calories each day and the men 600 calories per day.
Following these fasts, the participants were found to have lost an average of around 17 pounds—roughly 7.8 percent of their average body weight.
The authors also found that the patients' microbiomes changed, with some bacterial species increasing sharply in numbers while others, including Escherichia coli, fell.
E. coli is a common bacterium, and some strains cause such sicknesses as diarrhea, urinary tract infections, respiratory illness and pneumonia.
"Significant alterations were observed in certain gut bacteria abundances due to the IER diet, including pathogenic E.coli as well as obesity-related probiotics Faecalibacterium prausnitzii, Parabacteroides distasonis, and Bacterokles uniformis. However, it should be noted that data regarding the gut microbiome is extensive; therefore further research is required to explore specific microbial populations involved in weight loss," Zeng said.
The researchers reported that certain regions of the brain associated with the regulation of appetite and addiction saw decreased activity levels after the fasts and said this was a result of the microbiome changes.
The team found that a high abundance of some bacteria, including E. coli, was associated with reduced activity in the region of the brain that plays a role in willpower when losing weight.
They also found that an abundance of other species of bacteria was positively correlated with increased activity in brain regions associated with attention, motor inhibition, emotion and learning.
"The gut microbiome is thought to communicate with the brain in a complex, two-directional way," said paper co-author Xiaoning Wang of the Institute of Geriatrics at the PLA General Hospital in a statement.
"The microbiome produces neurotransmitters and neurotoxins which access the brain through nerves and the blood circulation. In return the brain controls eating behavior, while nutrients from our diet change the composition of the gut microbiome," Xiaoning said.
This implies that changes in the brain and changes in the microbiome after weight loss affect each other.
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