# Role of Nutribiotics in Skin Care
## 5 Nutribiotics: An Opportunity to Improve Skin Health
### Wound Healing  
It has been shown that the absence of microbiota can decrease healing time; furthermore, wound infections appear when exogenous bacteria become dominant over systemic and local host resistance factors, and only when a balance is achieved between bacteria and the host can healing processes develop [230]. The most effective wound management strategy is to prevent infections, promote healing, and prevent excess scarring, and probiotics may aid in skin repair by exerting antagonistic effects against pathogens and stimulating the production of immune cells [231]. In a comprehensive review performed by [PERSON] et al. [162], the authors found that the most commonly used probiotics against pathogens of wound infections were well-known strains of the species _Lactobacillus plantarum_, _Lactobacillus casei_, _Lactobacillus acidophilus_, and _Lactobacillus rhamnosus_. All in vitro studies showed effective inhibitions of wound pathogens by selected probiotics. In all in vivo studies, probiotics showed strong activities in counteracting wound infections. Most clinical studies showed a mild or statistically significant lower incidence of surgical site infection, foot ulcers, or burn infections in patients using probiotics [162]. [PERSON] et al. [232] investigated the effect of the perioperative oral administration of probiotics on the healing of skin wounds in rats. The probiotic group was supplemented with _Lactobacillus paracasei_ LPC-37, _Bifidobacterium lactis_ HN0019, _Lactobacillus rhamnosus_ HN001, and _Lactobacillus acidophilus_ NCFM(r) (Raleigh, NC, USA) at a dose of 250 mg/day, and the control group was supplemented with oral maltodextrin 250 mg/day, both daily for 15 days. In the intervention group, a faster reduction in the wound area was observed, and the authors postulated that this may probably be attributed to a reduction in the inflammatory phase, an acceleration of the fibrosis process, and collagen deposition. On the other hand, [PERSON] et al. [233] conducted a systematic review focused on the currently available evidence on the effect of enteral or oral probiotictic therapy on wound healing both of the skin and oral mucosa, which included seven studies involving 348 people. The results showed that four studies reported positive results for better healing after probiotictic therapy, and none of the studies reported adverse effects or increases in wound healing time. The authors concluded that the results do not generate strong evidence regarding the effectiveness of probiotictics for wound healing. Later on, [PERSON] et al. [234] revised the role of probiotics in chronic wounds, finding 14 articles and concluding that probiotics help eliminate pathogenic bacteria and restore normal wound flora when applied topically. The main probiotic strains were from the _Lactobacillus_ species: _L. plantarium_, _L. acidophilus_, _L. rhamnosus_, and _Saccharomyces cerevisiae_[234]. _S. cerevisiae_ was shown to achieve an overall improvement in the healing process; specifically provoking an increase in the expression levels of collagen type 1 and transcription growth factor beta 1 (TGF-81), as well as an improvement in the morphological and biomechanical characteristics of the healing wounds [235]. In vitro study _L. acidophilus_ and _L. casei_ demonstrated antibacterial activity against Methicillin-resistant _Staphylococcus aureus_[236]; and _L. reuteri_ and _L. rhamnosus_ reduced the ability of the pathogen to induce keratinocyte cell death [237]. Additionally, _L. fermentution_ showed an increased wound closure concurrent with the production of nitric oxide (gNO) [238]. Recently, [PERSON] et al. [239] revised the relationship between the skin microbiome and the wound healing process. Most of the studies (as in the previous revision by [PERSON] et al.