Lactobacillus kefiranofaciens is a probiotic bacterium commonly found in kefir grains and has been studied for its immunomodulatory effects. There is some scientific research suggesting that L. kefiranofaciens can influence gut-associated lymphoid tissue (GALT), which includes Peyer’s patches—important structures in the small intestine that play a key role in immune surveillance and initiation of immune responses. Animal studies have demonstrated that administration of L. kefiranofaciens or its polysaccharide kefiran can enhance the number and activity of immune cells in Peyer’s patches, increase the production of immunoglobulin A (IgA), and modulate cytokine profiles, suggesting a possible benefit for gut immune health.

However, while these findings are promising and provide a scientific rationale for the use of L. kefiranofaciens to support the Peyer’s patches and gut immunity, most evidence is preclinical (e.g., rodent models). There is a lack of robust, high-quality human clinical trials directly linking L. kefiranofaciens supplementation to improved function of Peyer’s patches or related immune outcomes in humans. Therefore, the evidence supporting its use is emerging but limited, meriting a moderate-low rating until more human data are available.