# The Antiviral Potential of Probiotics--A Review on Scientific Outcomes
## 4 Clinical Studies on the Antiviral Potential of Probiotics
The results suggested that GandeenBC\({}^{30}\) may be a safe and potent probiotic for the treatment of respiratory viral infection [60]. The nursing home residents were supplemented with the probiotic strain _L. rhamn_s GG (10\({}^{9}\) CFU per capsule/two capsules per day) for six months, and then its impact on influenza and other viral infections was analyzed. Probiotic intervention showed about 15% of viral infections among the study subjects of probiotic group, whereas the placebo group showed 22.9% of infection among the study subjects. Although the probiotic group showed some protective activity against viral infection, further studies are needed to confirm the findings with a larger group of people [61]. The probiotic strains with in vitro antiviral activity have been studied for the efficiency to reduce the symptoms of viral gastroenteritis in pediatric patients. A mixture of _B. longum_, _Bifidobacterium lactis_, _Lactobacillus acidophilus_, _L. rhamn_s, _L. plantarum_ and _Pediococcus pentosacus_ strains were supplemented to patients (10\({}^{9}\) CFU twice a day) for one week. These strains effectively reduced the duration of diarrhea compared to the placebo control without any adverse effects, which suggested that the use of potent probiotics could nullify the severity of viral gastroenteritis in children [62]. The effect of _L. rhamn_s 35 supplementations on fecal rotavirus shedding was studied in children with acute rotavirus gastroenteritis. The children were administrated with 2 or 6 \(\times\) 10\({}^{8}\) CFU of _L. rhamn_s 35 or a placebo for three days. The fecal samples were analyzed for the changes in the viral particle count compared with the baseline. There was no change in the placebo and the 2 \(\times\) 10\({}^{8}\) CFU treated group in terms of fecal viral shedding. However, the supplementation of 6 \(\times\) 10\({}^{8}\) CFU _L. rhamn_s 35 for three days reduced about 86% of the fecal viral shedding in children. The results indicated that the dose of probiotic supplements has a vital role in treatment efficiency [63]. The supplementation of BifilacTM for 14 days significantly reduced the number of episodes and the mean duration of diarrhea in children (3-36 months old). Additionally, the dehydration rate, the need for rehydration and intravenous fluid therapy reduced when compared to the placebo. Importantly, the BifilacTM supplementation reduced the rotavirus shedding significantly. The study claimed that the use of BifilacTM is safe and adjuvant for acute rotavirus treatments [64]. The influence of the supplementation of a probiotic (_L. rhamn_s GG) and prebiotics (galactooligosaccharide and polyed dextrose mixture) on rhinovirus infection-associated respiratory tract infections (RTIs) in preterm infants has been studied. _L. rhamn_s GG (1 \(\times\) 10\({}^{9}\) CFU per day for 30 days, and 2 \(\times\) 10\({}^{9}\) CFU per day for 31-60 days) and a mixture (1:1) of galactooligosaccharide and polyed dextrose (1 \(\times\) 600 mg/day for 30 days, and 2 \(\times\) 600 mg/day for 31-60 days) were supplemented to infants. During the 60 days of the intervention period, the incidence, duration and severity of the RTIs were measured. The probiotic and prebiotic supplemented group showed a significantly low frequency of RTIs compared to the placebo group. Similarly, the number of RTI episodes were reduced in the probiotic and prebiotic supplemented groups. There were no adverse effects and no change in rhinovirus RNA shedding, viral RNA load or the severity of rhinvirs infection among the study subjects. The results suggested that the use of prebiotics and probiotics could prevent rhinoval infection by modulating the composition of gut microbiota [65]. The effect on the response of chemokine (C-X-C motif) ligand 8 (CXCL8) to rhinovirus infection in probiotic (_Bifidobacterium animalis_ subspecies _lactis_ Bl-04)-supplemented healthy subjects have been studied.