Simple SummaryRecent research studies have revealed that probiotics such asLactobacillusare good antibiotic alternatives in the poultry industry. We previously isolatedLactobacillus reuteriSL001 from the gastric contents of rabbits and proved that dietary inclusion of SL001 could positively improve the composition of the intestinal bacterial community in Alzheimer’s disease model mice. In the present study, we explored the effects of dietary SL001 on growth performance, health-related parameters, intestinal morphology and microbiota of broiler chickens. Our results showed that SL001 supplementation in diets promoted the growth performance of broilers, strengthened immunity, and improved antioxidant stress as well as intestinal morphology and microbiota, implying its potential application in boiler feeding.AbstractIt was assumed that dietary inclusion ofLactobacillus reuteriSL001 isolated from the gastric contents of rabbits could act as an alternative to feed antibiotics to improve the growth performance of broiler chickens. We randomly assigned 360 one-day-old AA white-feathered chicks in three treatments: basal diet (control), basal diet plus zinc bacitracin (antibiotic), and basal diet plusL. reuteriSL001 (SL001) treatment. The results showed the total BW gain and average daily gain (ADG) of broilers in SL001 treatment increased significantly (p< 0.05, respectively) compared with the control group from day 0 to 42. Moreover, we observed higher levels of immune globulins in both the SL001 group and the antibiotic group. Total antioxidant capacity and levels of antioxidant factors were also significantly increased (p≤ 0.05, respectively) in the SL001 treatment group, while the interleukin 6, interleukin 4, creatinine, uric acid, total cholesterol, triglyceride, VLDL, LDL and malondialdehyde were remarkably decreased (p< 0.05, respectively). In the ileum of SL001 treatment broilers, the height of villi and the ratio of villi height to crypt depth were significantly increased (p< 0.05). Meanwhile, the crypt depth reduced (p< 0.01) and the ratio of villi height to crypt depth increased (p< 0.05) in the jejunum compared to the control. The abundance of microbiota increased in the gut of broilers supplemented with SL001. Dietary SL001 significantly increased the relative abundance of Actinobacteria in the cecal contents of broilers (p< 0.01) at the phylum level. In conclusion,L. reuteriSL001 supplementation promotes the growth performance of broiler chickens and exhibits the potential application value in the industry of broiler feeding.