The normal flora in human's intestine is a very important in microecological system.Among them,anaerobe is 99% absolute
dominance and the majority of the them is
bifidobacteria(95%).In this study,the changes of
intestinal flora of 41 cases were observed, among which 30 cases belonged to testing group treated with smectite and 25 cases to control group with persin mixture(MP)before and after treatment by the technology of regular bacteriology and bacterial molecular biology to detect the change in 4 kinds of bacteria(two of them were anaerobe which were bifidobacteria and bacteroid, other two were aerobe which were enterococcus and enterobacteria) stood for alteration of intestinal flora. The result showed that before treatment,the intestinal flora of all diarrheal children have changed obviously. Among anaerobe, the populations of bifidobacteria and bacteroid decreased significantly. whereas the number of aerobe relatively increased. The ratio of anaerobe to aerobe decreased from 1000:1 to 1:1.As a result,the patients'inrestinal flora altered and disordered. After five days of treatment with smectite(5-day cure rate is 96.67%).the alteration of intestinal flora recovered at some extent,the populations of Bifidobacteria increased 158 folds.Whereas there was no significant change in number of other 3 kinds bacteria.However,in control group treated with MP(5-day cure rate is 68.00%),the state of flora imbalance hadn't been improved.In the followed two week's trace investigation,we didn't find any case of smectite group to recur,but 11.76% cases in control group recurred. The results indicated that of important mechanisms of smectite is that it enchances the growth of anaerobe in intestine and inereases the level of intestinal bifidobacteria so that it can adjust the alteration of intestinal flora and reinforce the barrier action of microorgnisms, beside it can adhere to pathogens and excrete it, reinforce intestinal mucosal barrier and help regeneration of epithelimu.In conclusion, smectite has significant efficiency and endurance and is a kind of microecological adjustment agents.