Which two pro-inflammatory bacteria were hypothesized to be abundant in the intestinal biopsies of cats with small cell GI lymphoma relative to cats with IBD?

• A. Bacteroides and Prevotella
• B. Streptococcus and Staphylococcus
• C. Enterobacteriaceae and Fusobacterium spp.
• D. Lactobacillus and Bifidobacterium

Answer: (C)

The main idea is that the gut microbial community can show distinct pro-inflammatory patterns when the GI tract is affected by cancer versus inflammatory disease. In this feline comparison, the two pro-inflammatory groups hypothesized to be more abundant in the intestinal biopsies of cats with small cell GI lymphoma than in cats with IBD are Enterobacteriaceae and Fusobacterium spp. Enterobacteriaceae includes Gram-negative rods like E. coli that produce lipopolysaccharide and strongly stimulate mucosal inflammation, a common feature of gut dysbiosis associated with inflammatory conditions. Fusobacterium spp., especially Fusobacterium nucleatum, can adhere to and invade epithelial cells, activate inflammatory signaling, and promote a pro-tumor microenvironment in the gut, a pattern linked to malignancy and inflammation in multiple species. These taxa fit the idea of a lymphoma-specific inflammatory microbiota. In contrast, bacteria like Lactobacillus and Bifidobacterium are typically seen as beneficial and anti-inflammatory, so they are less likely to be the taxa expected to be enriched in lymphoma relative to IBD.