Impact of oral consumption of heat-treated Bacteroides xylanisolvens DSM 23964 on the level of natural TFα-specific antibodies in human adults

It is now generally accepted that the human body exists in close synergy with the gut microbiome and that this cross-talk plays an essential role in human health and disease. One facet from the many interactions between the microbiome and the immune system is the induction of natural antibodies to commensal bacterial glycans, such as blood group antigens, the alpha-Gal epitope or the Thomsen-Friedenreich (TF alpha) antigen. Since we have observed that certain species of the commensal genus Bacteroides express the TF alpha antigen, we examined whether the oral dietary supplementation of a pasteurised Bacteroides xylanisolvens strain might be able to enhance the level of natural anti-TF alpha antibodies in healthy adults. The data obtained from a double-blind, placebo-controlled study involving 140 healthy volunteers and lasting 8 weeks revealed that the oral uptake of this strain was indeed able to increase the level of TF alpha-specific immunoglobulin M serum antibodies. The effect was dose-dependent but remained - at any doses - within the physiological range determined before intervention. Furthermore, the effect reverted after stopping the intake. The results support the idea of the microbiome inducing the generation of systemic antigen-specific antibodies against sugar epitopes. They also demonstrate the possibility to modulate essential regulatory or defence processes through dietary supplementation of selected commensal bacteria with the aim to assist human health.