https://www.selleckchem.com/products/sb273005.html Maternal nutrition during gestation and lactation is essential for offspring's health. The present study aimed to investigate the effects of betaine hydrochloride addition to sow diets during gestation and lactation on suckling piglet's immunity and intestine microbiota composition. Forty Bama mini-pigs were randomly allocated into two groups and fed a basal diet (control group) and a basal diet supplemented with 3.50 kg ton betaine hydrochloride (betaine group) from day 3 after mating to day 21 of lactation. After 21 days of the delivery, 12 suckling piglets from each group with similar body weight were selected for sample collection. The results showed that maternal betaine hydrochloride addition decreased (P < 0.05) the plasma levels of interleukin (IL)-1β, IL-2, IL-6, and tumor necrosis factor-α in suckling piglets. Furthermore, dietary betaine hydrochloride addition in sow diets increased (P < 0.05) the villus height (VH) and VH to crypt depth ratio in the jejunum and ileum of suckling piglets. In the piglets' intestinal microbiota community, the relative abundances of Roseburia (P < 0.05) and Clostridium (P=0.059) were lower in the betaine group compared to those in the control group. Moreover, betaine hydrochloride addition in sow diets decreased the colonic tyramine (P=0.091) and skatole (P=0.070) concentrations in suckling piglets. Betaine hydrochloride addition in sow diets enhanced the intestinal morphology, improved immunity, and altered intestinal microbiota of suckling piglets. These findings indicated that betaine hydrochloride addition in sow diets during gestation and lactation will impact suckling piglets' health. © 2021 Society of Chemical Industry. Betaine hydrochloride addition in sow diets enhanced the intestinal morphology, improved immunity, and altered intestinal microbiota of suckling piglets. These findings indicated that betaine hydrochloride addition in sow diets during gestation and lac