The results of this study revealed that the rate of AAD was lower in the probiotic group than in the zinc group. However, the difference between the groups was not statistically significant. The control group had an AAD that fell between those of the other two groups.
On the other hand, the probiotic group had significantly shorter hospitalization and treatment durations than did the zinc group. This finding contrasts with that of Kodam's study, which revealed that, compared with probiotics, zinc was more effective at reducing diarrhea recovery time (13). Both treatments had similar effects on stool consistency and frequency, but zinc was more effective overall. Similarly, Ahmadpour et al. reported that zinc was more effective than probiotics in treating acute diarrhea in children. Additionally, the side effects of zinc treatment are less severe than those of probiotics(14).
Hassan et al. investigated the effectiveness of oral zinc and probiotics on AAD in children(15). Their study included a third group that received both zinc and probiotics. These results were inconsistent with those of the present study, as they reported that the combination treatment was more effective than either treatment alone. These studies had designs similar to those of the present study, which compared zinc and probiotics in separate groups(13, 14, 15). However, there were differences in the entry and exit criteria, demographics, dosage and form of zinc, content of probiotics, and type of diarrhea being studied. These variations, along with differences in the studies' purposes (prevention or treatment of diarrhea), likely explain the contrasting findings.
The probiotics used in the present study contained different types of bacteria, which may explain why they were more effective than zinc. The findings of Huang et al. support this idea, as they reported that a combination of probiotics was more effective at reducing the duration of diarrhea than a single probiotic was (16).
Importantly, neither zinc nor probiotics were superior to the control group in terms of hospital stay and duration of treatment. A systematic review and meta-analysis by Huang et al. revealed that probiotics shortened the duration of diarrhea and reduced the effectiveness of two-day treatment. The probiotic group also had shorter hospitalization (16).
In another study, Azim et al. compared the combination of zinc and probiotics to zinc alone in treating acute gastroenteritis in children. The combination treatment was significantly more effective. Hassan et al. reported similar results, suggesting that the combination treatment was more effective than either treatment alone!17).
These findings suggest that the combination of zinc and probiotics may be a better option for treatment or prevention than either treatment alone. Future studies should consider including a zinc-containing probiotic arm in addition to zinc, probiotics, and control arms to provide more conclusive results.
Xiang et al. reported that zinc in combination with probiotics was more effective than probiotics alone in treating antibiotic-induced diarrhea caused by pneumonia in children(18).
Tai et al.'s clinical trial revealed that zinc supplementation reduced the duration of AAD in hospitalized children but did not affect disease severity except on the sixth day(19). Zarin Far et al. reported that Lactobacillus probiotics did not significantly reduce AAD but did alleviate colitis symptoms(20).
5.1. Conclusion
In summary, this study contributes to the literature by examining the effectiveness of zinc and probiotics in treating AAD in children. The combination of zinc and probiotics may be more effective than either treatment alone. However, further research is needed to provide more definitive conclusions. The findings of the present study revealed that the prevalence of AAD was lower in the probiotic group than in the zinc group. Importantly, however, the disparity between the two groups did not reach statistical significance.