Page 663 - Veterinary Immunology, 10th Edition

It may be relevant to note here that the distribution of TLRs on cells
VetBooks.ir differs significantly between conventional and germ-free pigs.

Microbiota Signals to the Body

Bacteria, be they on the skin, respiratory tract, genital tract, or

intestine, communicate directly and effectively with their host's
immune system. Indeed, this interaction is essential to the proper
functioning of the innate and adaptive immune responses.

Alterations or imbalances in the microbiota therefore have
profound effects on the functions of the immune system. The
proper interaction between the immune system and the microbiota
is required for optimal health.
Dietary plant fibers contain complex carbohydrates. When

digested by Clostridia in the cecum and colon, these complex
carbohydrates generate large amounts of short-chain fatty acids
(SCFAs) such as butyrate, propionate, and acetate that suppress
+
macrophages and promote production of intestinal Foxp3 Treg
cells (Fig. 21.7). Butyric acid has antiinflammatory effects since it
acts on macrophages and prevents epigenetic changes by inhibiting
histone deacetylases. Butyrate also increases barrier functions by
stimulating enterocytes and increasing transcription of mucin

genes, goblet cell differentiation, and mucus production. It can also
stimulate some bovine neutrophil functions. As a result, high-fiber
diets play a key role in regulating intestinal inflammation.

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