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[Effects of fine particulate matter on cognitive function and gut microbiota in adult male mice]
Yanfang Wu1, Jin Yin1, Wa Cao1
1School of Public Health, North China of Science and Technology, Tangshan 063210, China.
Objective:
To study the effects of fine particulate matter(PM_(2.5))exposure to cognitive function and intestinal flora abundance and diversity in adult male mice.
Methods:
The SPF grade male C57 BL/6 J mice with 8 weeks old were randomly divided into control group(NS group), PM_(2.5) exposure group(PM_(2.5) group), probiotic group(VSL#3 group) and PM_(2.5) + VSL#3 group(PMV group), with 8 mice in each group. The PM_(2.5) group and PMV group mice were exposed to PM_(2.5) using animal exposure system equipped with real-time PM_(2.5) concentration, and concentrated 6 times the outdoor PM_(2.5) concentration, 8 h every day, 5 d every week for 4 weeks. The VSL#3 group and PMV group mice were given VSL#3, 0.5 mL, 2×10~9 CFU/mL. After four weeks of exposure, feces from mice were collected for 16 s rRNA high-throughput sequencing, and the cognitive function was evaluated using Morris water maze and object recognition experiments.
Results:
The escape latency of PM_(2.5) group in four-day training [(54.99±6.77) s, (41.21±9.98) s, (36.27±13.11) s, (30.01±14.80) s] were higher than that of NS group [(32.19±4.59) s, (20.50±6.77) s, (19.93±7.30) s, (16.94±9.91) s], and the difference were statistically significant(P<0.05). The escape latency of PMV group on the first and second day of training [(39.02±6.23) s, (28.83±9.53) s] were lower than that of PM_(2.5) group(P<0.05). The target quadrant residence time of mice in PM_(2.5) group [(18.30± 8.88) s] was lower than that in NS group and PMV group [(30.53±9.10) s, (30.00±10.61) s]. Compared with NS group(6.09±0.40), the shannon index of PM_(2.5) group and PMV group(5.05±0.65 and 5.46±0.52) were significantly reduced(P<0.05). The target quadrant time was positively correlated with the relative abundance of Actinomyces(r=0.576, P<0.05), and the recognition index was positively correlated with the relative abundance of Firmicutes(r=0.612, P<0.05).
Conclusion:
PM_(2.5) could lead to cognitive dysfunction in mice, which is related to diversity and abundance of the intestinal flora. Probiotic can improve cognitive function.
Insights
Exposure to fine particulate matter (PM2.5) impaired cognitive function in mice by altering gut microbiota. Probiotic treatment partially restored cognitive abilities, suggesting a link between gut health and brain function.
Area of Science:
- Environmental Health
- Neuroscience
- Microbiology
Background:
- Fine particulate matter (PM2.5) exposure is a growing environmental concern.
- Emerging evidence suggests a gut-brain axis linking intestinal microbiota to cognitive function.
Purpose of the Study:
- To investigate the impact of PM2.5 exposure on cognitive function and gut microbiota in adult male mice.
- To evaluate the potential protective effects of probiotic VSL#3 against PM2.5-induced changes.
Main Methods:
- Adult male C57 BL/6 J mice were exposed to PM2.5 or control conditions for 4 weeks.
- Cognitive function was assessed using the Morris water maze and object recognition tests.
- Gut microbiota composition was analyzed via 16S rRNA high-throughput sequencing.
Main Results:
- PM2.5 exposure significantly increased escape latency and reduced target quadrant residence time, indicating cognitive impairment.
- PM2.5 exposure reduced the diversity of gut microbiota (Shannon index).
- Probiotic treatment (VSL#3) partially ameliorated cognitive deficits and gut microbiota alterations.
Conclusions:
- PM2.5 exposure induces cognitive dysfunction in mice, associated with reduced gut microbiota diversity and altered abundance.
- Probiotic administration shows potential in mitigating PM2.5-induced cognitive impairment, highlighting the role of the gut microbiota.
