The in vitro study found distinct differences in the starting microbial communities in lean and obese samples. Apple fibers, particularly pectin, boosted beneficial species such as Akkermansia in the obese microbial community and increased beneficial metabolites.
The findings add further evidence to the role of diet and the microbiome in tackling obesity, highlighting the benefits of a personalized approach.
“This in vitro study suggests that incorporating apple fibers into the diets of obese individuals can help modify the composition of gut bacteria and improve metabolic health,” researchers in the Netherlands and Spain wrote. “This personalized approach could help mitigate the effects of obesity.”
Influencing the microbial landscape
Increasing evidence suggests a pivotal role of diet in influencing the gut microbiota and risk of metabolic diseases.
Obesity is https://onlinelibrary.wiley.com/doi/full/10.1155/2018/4095789, and probiotics have emerged as potential anti-obesity agents.
Although the exact mechanisms have yet to be confirmed, studies suggest that gut microbes influence weight and adiposity by affecting gene expression, inflammatory pathways and the gut-brain axis. Certain bacteria are thought to protect against visceral fat, and the absence of these species is associated with obesity.
Diet can modulate the microbiome and alter the diversity of bacteria. Dietary fibers in plant-based foods act as prebiotics for gut bacteria, maintaining diversity and producing short-chain fatty acids (SCFAs).
SCFAs have many health benefits, including anti-inflammatory, gut-protective, anti-obesity and immunoregulatory properties.
However, although dietary fiber is known to benefit the gut, its effects may vary from person to person, highlighting a need to tailor dietary interventions to a person’s gut microbiota.
“In other words, personalizing the diet based on individual needs and health conditions is essential for maximizing its effectiveness,” the current study noted.
Study details
The in vitro study collected stool samples from healthy, lean and obese individuals and used a bioreactor to simulate the digestion of apple, apple pectin and cellulose and their subsequent colonic fermentation.
The researchers used multi-omics analysis to identify the key microorganisms and metabolites involved.
Initial data suggested that obese and lean microbial communities had distinct starting microbial communities. The apple fibers, particularly pectin, reduced Acidaminococcus intestini and boosted Megasphaera and Akkermansia in the obese microbial community. The fibers also increased the production of beneficial indole microbial metabolites.
“We found that the obese microbial community had higher branched-chain amino acid catabolism and hexanoic acid production, potentially impacting energy balance,” the researchers wrote.
They found that apple pectin affected species like Klebsiella pneumoniae and consistently modulated the abundance of Bifidobacterium longum.
They noted that previous animal studies have shown a negative correlation between this species and obesity, lowering body weight, reducing fat deposition and improving glucose tolerance.
In addition, they noted a “mutualistic cross-feeding relationship between Megasphaera sp. MJR8396C and Bifidobacterium adolescentis”.
The researchers indicated that the different effects on the microbial communities observed in the lean and obese samples suggest that dietary fiber’s impact depends on the gut’s initial microbial composition.
They called for further studies to confirm their results and explore the potential for personalized dietary interventions to improve metabolic health.