The study, published last month in the Proceedings of the National Academy of Sciences of the United States of America (PNAS), concludes that fluid flow, such as water intake, impacts the organisation and composition of gut biofilm communities.
These gut biofilms, formed by bacterial commensals, interact metabolically with each other, sharing the metabolic by-products of the polysaccharide dextran, which in turn promotes the formation of more biofilms.
The researchers, from the Swiss Federal Institute of Technology Lausanne, found that strong fluid flow prevented the formation of specific biofilms by reducing the concentration of the beneficial metabolic by-products at the surface.
“Theory predicts that intestinal flow and peristaltic mixing can have a strong impact on microbiota diversity and spatial organisation and has been validated with an engineered cross-feeding community of E. coli,” the study authors wrote.
“Still, the mechanisms by which anaerobic microbiota species interact metabolically in a mechanically realistic environment have yet to be demonstrated, in particular in the context of biofilms, a lifestyle that has been overlooked in investigations of the human gut microbiota.”
Water’s role in prebiotic, probiotic, synbiotic, and postbiotic efficacy
The study may well raise questions regarding how best to administer gut-friendly supplements such as prebiotic, probiotic, synbiotic, and postbiotic formulations.
Specifically, the study encourages debate as to which delivery method or format best suits the administration of these supplements to ensure maximum efficacy. Current product formats include pills, capsules, and powders, as well as gummies, suppositories, and liquids.
Mindful of the impact of water flow in building gut bacterial communities, UK-based supplement firm Symprove’s probiotic supplement range employs a water-based delivery system that is combined with a liquid barley extract.
This approach allows the bacterial blend of Lactobacillus rhamnosus, Enterococcus faecium, Lactobacillus acidophilus, and Lactobacillus plantarum to pass straight through to reach the target gut areas without activating digestion.
“Symprove appears to have clinical efficacy in part because its water-based formulation is effective at protecting the probiotic bacteria from the challenges of oral delivery,” concluded a 2019 study by a team from University College London that looked at the use of Symprove’s water-based probiotic to treat common gut pathogens.
“In vivo, consumption of water does not trigger production of stomach acid by converting it to pepsin.”
Water an ‘overlooked’ nutrient when it comes to gut health
Of course, critics of the influence of fluid flow in gut health simply point to the pills, capsules, and powders that biotic supplements are available in, arguing that these need to be taken with water anyway to ease delivery of their payload to the gut.
The main issue here is maintaining the viability and colony-forming unit (CFU) numbers of the biotic within the format, as well as ensuring successful delivery to the correct area of the gut.
But regardless of fluid flow’s effect on gut health, the mere act of consuming a fluid such as water with or without one of these supplements appears to benefit the gut microbiome and its diverse communities.
Results of another study reinforced water’s status as an important factor in shaping the human gut microbiome, and showed that integrating drinking water source and intake as covariates in future microbiome analyses is warranted.
“The mechanisms by which drinking water may interact with microbial communities, if any, remain to be elucidated but could involve water pH, solute and mineral composition, natural intrinsic microbial communities, or residual chlorine and disinfection by-products that remain in most tap waters,” the authors stated.
Water intake likely to impact ‘multitude of different bacteria’ in human gut
Commenting on the PNAS study and its relevance to daily water intake, Dr Frank Bernier, an Alzheimer’s and brain microbiome expert, wrote in a LinkedIn post: “[D]rinking an adequate amount of water could be vital in maintaining a healthy gut microbiota by providing a suitable environment for beneficial biofilm formation and metabolic interactions.
“Consuming at least one litre of water a day may help regulate the fluid flow in the gut, ensuring a balance that allows for the metabolic by-products (like those from dextran fermentation) to support the growth of beneficial bacteria.”
He added: “It’s important to note that while the abstract specifically discusses Bacteroides thetaiotaomicron (Bt) and Bacteroides fragilis (Bf) bacteria, the human gut contains a multitude of different bacteria, and water intake likely impacts these other species in complex ways as well.
“As such, adequate hydration is a key element for optimal gut health, which can influence overall health and well-being.”