Evaluation of the orally administered calcium alginate aerogel on the changes of gut microbiota and hepatic and renal function of Wistar rats.

The present study evaluates the effect of calcium alginate aerogel as a potential drug carrier, on the liver and kidney functions, and on the gut microbiota of Wistar rats. The studied alginate aerogel was prepared in the form of nanoparticles using the jet cutting technique, and they were characterized in terms of specific surface areas, outer morphology and particle size distribution. For the in vivo study, calcium alginate aerogel was administered orally, and liver and kidney functions were tested for one week and for four weeks in two distinct studies. During the short-term in vivo study, feces samples were collected for bacterial DNA extraction followed by 16S rRNA gene sequencing analyses to detect changes in gut microbiota. Results showed that the prepared alginate aerogel has an average BET-specific surface area of around 540 m2/g, with a pore volume of 7.4 cc/g, and pore width of 30-50 nm. The in vivo study revealed that the levels of the studied kidney and liver enzymes didn't exceed the highest level of the normal range. The study of gut microbiota showed different patterns; certain groups of bacteria, such as Clostridia and Bacteriodia, increased during the aerogels regime and continued to increase after the aerogel was stopped. While other groups such as Erysipelotrichia, and Candidatus saccharibacteria increased during aerogels treatment, and then decreased again after one month. Members of the Bacilli class showed a unique trend, that is, after being the most abundant group (63%) at time 0, their relative abundance decreased dramatically until it reached < 5%; which was the case even after stopping the aerogel treatment.