Objective:To observe the effect of bacteroides fragilis BF839 intervention on learning, memory and social novelty of fragile X-mental retardation gene 1 ( Fmr1) knockout (KO) mice. Methods:Thirty three-week-old Fmr1 KO mice were randomly divided into Fmr1 KO group ( n=15) and Fmr1 KO+BF839 group ( n=15). Mice in the Fmr1 KO group freely drank autoclaved tap water everyday; mice in the Fmr1 KO+BF839 group drank BF839 bacterial liquid (10 mL/d) everyday;11 wild-type mice freely drank autoclaved tap water everyday were set as controls (WT group). After 4 weeks of intervention, Morris water maze test was used to observe the differences in escape latency and frequencies of crossing the original platform among mice in each group; Three-chamber Social Interaction Test was used to observe the differences in contact frequencies and contact durations with unfamiliar mice among mice in each group. Results:On the 4 th d of experiment, the escape latency of mice in the Fmr1 KO group ([46.06±10.29] s) was significantly longer than that in the WT group ([33.39±12.02] s, P<0.05); the escape latency of mice in the Fmr1 KO+BF839 group ([28.39±9.07] s) was significantly shorter than that in the Fmr1 KO group ( P<0.05); the escape latency of mice in the Fmr1 KO+BF839 group was slightly shorter than that in the WT group without significant difference ( P>0.05). The frequencies of crossing through the original platform of mice in Fmr1 KO group (0.00[0.00, 1.00] time) was slightly less than that in WT group (1.00 [0.00, 1.00] time) without significant difference ( P>0.05); that in the Fmr1 KO+BF839 group (1.50[1.00, 2.00] times) was significantly larger than that in the Fmr1 KO group and WT group ( P<0.05). The contact frequencies of the mice in the Fmr1 KO group with unfamiliar mice (5.50[0.50, 12.75] times) was less than that in the WT group (7.00[4.00, 17.00] times) without significant difference ( P>0.05); that in the Fmr1 KO+BF839 group (23.00[16.00, 36.00] times) was significantly increased as compared with that in the Fmr1 KO group and WT group ( P<0.05). The contact duration of mice in the Fmr1 KO group with unfamiliar mice (9.50[0.50, 41.95] s) was significantly shorter than that in the WT group (142.00[65.00, 171.60] s, P<0.05); Fmr1 KO+BF839 group had significantly longer contact duration with unfamiliar mice (69.60 [50.40, 98.40] s) than Fmr1 KO group ( P<0.05); the contact duration of mice in Fmr1 KO+BF839 group with unfamiliar mice was shorter than that in WT group without significant difference ( P>0.05). Conclusion:Early BF839 intervention can significantly improve the learning, memory abilities and social novelty of Fmr1 KO mice, and even restore the Fmr1 KO mice to normal levels, which suggests that BF839 may become a new tool for treatment of fragile X syndrome and autism.

Psoriasis is considered as an inflammatory disease driven by T cells, and its pathogenesis is closely related to the imbalance of intestinal bacteria flora. It has been reported that Bacteroides fragilis could play an anti-inflammatory role by regulating the expression of cytokines in T cells. To date, there is no report using B. fragilis to treat psoriasis. In this study, we explored the therapeutic effect of B. fragilis BF839 on psoriasis. We selected 27 psoriasis patients who were treated in the Second Affiliated Hospital of Guangzhou Medical University from April to October 2019. The patients were given B. fragilis BF839 orally for 12 weeks while maintaining the original treatment. The psoriasis area and severity index (PASI) score was evaluated before and after the treatment. The rate of drug withdrawal and reduction after 12 weeks of treatment were calculated. Our results showed that the rate of 12-week trial completion was 96.3% (26/27). We used PASIN to define the proportion of people whose PASI score decreased more than or equal to N% after treatment. At 12 weeks, PASI30, PASI50, and PASI75 were 65.4%, 42.3%, and 19.2%, respectively. The PASI score was 9.1±5.9 and 5.8±4.9 before and after 12 weeks of treatment respectively, and the difference was statistically significant (P<0.01). The effective rate of the visual analog scale (VAS) score was 42.3% at 12 weeks, and the VAS score was 2.9±2.2 and 2.3±2.1 before and after 12 weeks of treatment, respectively, which had no statistically significant difference (P>0.05). The adverse reaction rate of patients was 3.8% (1/26) within 12 weeks of treatment, including 1 case of constipation, and the rate of drug withdrawal and reduction was 60.0%. The above results suggest that B. fragilis BF839 may be functional on the treatment of psoriasis by reducing the PASI score and the drug usage rate with few side effect, which deserves further study.
Anti-Inflammatory Agents ; Bacteroides fragilis ; Cytokines ; Humans ; Psoriasis/drug therapy* ; Severity of Illness Index ; Treatment Outcome