Mixed strains of Lactobacillus are used to support or treat colitis, particularly ulcerative colitis and, to a lesser extent, other inflammatory bowel diseases. There is a moderate body of scientific evidence suggesting that certain probiotic mixtures containing Lactobacillus strains can benefit some people with colitis. Clinical trials and meta-analyses have shown that multi-strain probiotics, particularly those also containing Bifidobacterium, can help maintain remission in mild to moderate ulcerative colitis, though the results are variable and strain-specific. The most widely studied product is VSL#3, a high-potency probiotic containing multiple Lactobacillus species, which has demonstrated some efficacy in reducing disease activity and maintaining remission, especially when used as an adjunct to standard therapies.

The proposed mechanisms include modulation of the gut microbiome, enhancement of the mucosal barrier, and reduction of inflammation through immune modulation. However, the evidence is not uniformly strong: not all studies show positive effects, and the benefit appears to depend on the specific strains used, disease severity, and concurrent treatments. There is less evidence for the use of Lactobacillus in Crohn’s disease or severe colitis. Overall, current guidelines suggest probiotics may be considered as adjunctive therapy in mild to moderate ulcerative colitis, but they are not a replacement for conventional treatments. The evidence base has earned Lactobacillus a moderate rating (3/5) for this use.