Preventing Surgical Site Infections, Skin Microbiome Dysbiosis – The Fourth Dimension of Surgical Site Infection Epidemiological Quad
Year: 2025
Type: article
Abstract: From the times of Semmelweis and Lister, surgical practice has progressed exponentially from being lifesaving to improving patient-reported outcomes (PRO). Minimally invasive techniques like laparoscopic surgery have achieved clinical equivalence in terms of morbidity and mortality outcomes. Continuing advances in surgical techniques, sterile protocols, and perioperative antibiotic protocols have not diminished the challenges posed by surgical site infections (SSIs). SSIs are defined as infections occurring up to 30 days after surgery (1 year for surgeries with prosthesis implantation). They involve either the incision or deep tissue at the site of surgery. Three types of SSIs are described: Superficial incisional SSI-involve only the area of the skin incision Deep incisional SSI-involve the tissues under the incision (muscle and the surrounding tissue) Organ or space SSI involves any area of the body beyond skin, muscle, and surrounding tissue, including an organ or a space. Multiple, patient-related and procedure-related factors influence the risk of SSI, requiring a prophylactic “bundle” approach, with structured attention to these risk factors, apart from reducing the risk of bacterial contamination and improving immunity against infections. Emerging and evolving understanding of these factors and unknowns such as skin flora and its distribution or preservation calls for evaluating the scientific insights and implement them in our surgical practice appropriately.[1] SSIs are a serious concern as their consequences worsen both, the patient (morbidity and mortality) as well as the healthcare resource optimization indices. They lead to increased hospital stays, poor PROs, treatment costs increasing by three times, unfavorable scarring (both aesthetic and functional), and delayed adjuvant treatments in oncologic surgeries.[2,3] SSIs, the second-most frequent adverse event after hospitalization and second most frequent hospital-acquired infection, significantly increase the chances of 30-day rehospitalization and double the risk of mortality.[3] Hence, a scientific pursuit to address and reduce SSIs will improve the morbidity and mortality concerns besides reducing the financial stress on healthcare systems leading to the utilization of healthcare resources for the benefit of the population at large.[4] With a goal to standardize infectious risk assessment, perioperative protocol development, and surgical decision-making, a wound classification system was introduced by the National Academy of Sciences in 1964. It continues to guide perioperative protocols since then.[3] It categorized the surgical wounds into: clean, clean/contaminated, contaminated, and dirty. These categories of wounds have SSI rates being reported at 1%–5%, 3%–11%, 10%–17%, and over 27%, respectively.[5] These insights helped in developing guidelines for improved sterile protocol and peroperative antibiotic prophylaxis.[3] Laparoscopic surgery has been reported to have comparatively reduced SSI rates.[2] The risk of SSI is a multidimensional play of various preoperative risk factors like age, body mass index, nutritional status, substance abuse (nicotine/tobacco), physical activity status, comorbidities, American Society of Anaesthesiology grade, preoperative preparation (including hair removal and skin preparation) operating room ventilation, equipment sterilization, prophylactic antibiotic compliance, surgical procedure, surgical approach (open or minimally invasive), length of skin incision, operative time, and postoperative wound care.[4-7] All these risk factors belong to disease-causing “Host–Pathogen–Environment” epidemiological triad. A fourth dimension, i.e., the environment that we carry, the surface microbiome, being an important agent in health-disease equilibrium has been added, reshaping the triad to a quad.[8] Surgeons have been hailed as community leaders besides being scientists in their unparalleled pursuits demanding the application of all faculties of science collectively and in a lifesaving instant commissioned with spontaneous innovation while dealing with unexpected findings amidst surgery for uncommon complex clinical presentation in the presence of the latest technological tools, machine learning algorithms, and artificial intelligence guidance being at hand but of no avail.[9-13] Their practice goal of improved patient care with precise and informed clinical outcomes demands the incorporation of an innovative mind, understanding of the molecular basis of healing pathways, aware social responsibility about traditional/ancient wisdom, application of genetics and embryology teachings, pooled guidance from information technology dynamics and working with miniaturizing tools in this era of nanotechnology. It makes the surgeon an imagination-driven engineer, an imagineer, working on fellow human bodies putting his benefits secondary to clinical outcomes for his patient.[14] These are the attributes that make a surgeon perpetually working toward the horizon of clinical excellence in precision and challenging frontiers of evolving science despite, even the term “Surgical innovation,” being yet undefined, surgical research lacking a body equivalent to FDA for medical research, in a nation as developed as United Staes of America, and surgeons sometimes being causalities to slow-moving Institutional Review Boards, that are neither ideal for surgical research nor necessary at times, when a clearance from chief of surgery should suffice, as per the guidance from experts from American College of Surgeons.[15] Despite these handicaps, surgeons have been at the forefront of the epidemiological quad-based understanding being applied to enhance the respect to patients social background (an essential component of informed consent protocols), augment the stated goals of enhanced recovery after surgery, and accelerate convalescence after surgery with. This is an index of their imagineering in marrying the traditional wisdom with knowledge from modern science. This convergence of traditional wisdom with science made us the leaders in incorporating the benefits of probiotics in improving clinical outcomes in terms of dreadful adverse events like anastomotic Leaks et al. with unexpected gains in PROs.[16,17] The understanding about the benefits of probiotics is a result of surgeons being proactive in assimilating the knowledge about the microbiome concurrently with its evolution. The gut microbiome has been the index of surgical research with its reported benefits including reduced SSIs.[16] These benefits are a reflection of the dynamic bidirectional “skin-gut-skin” axis of physiological existence.[18-20] Human microbiome is being studied in other organs too. The skin microbiome is emerging as an important factor in maintaining skin immunity, protection, and prevention from infections. The skin microbiome acts as a team of prebiotics, probiotics, postbiotics, parabiotics, and synbiotics (4Ps) collectively, to provide immunity from infections. A probiotic being a beneficial microbe-enhancing skin microbiome, prebiotic being any substance that promoted the growth of probiotic, postbiotic are the molecules derived from the microbiome, parabiotic is the lysate products of a dying microbiome and synbiotic is the combination of pre and probiotic. To prevent skin infections it’s important to balance, improve the diversity of, and restore skin microbiome.[20] Our understanding about microbiome, being handicapped by culture based techniques, has been possible due to culture-independent multi-omic molecular techniques that identify the microbial genetic material, 16s ribonucleic acid or DNA (metagenomics, metatranscriptomics) or their molecular component (proteomics, lipidomics, and metabolomics). In addition to being a physical barrier and diverse microbiome carrier, the skin hosts many immunomodulatory cells, i.e., keratinocytes, sebocytes, Langerhans cells, T-cell populations, and dendritic cells. These cells respond to exogenous insults like skin incisions, etc., through signals that rebalance the microbiome diversity and colonization on demand to reduce inflammation, eliminate pathogens and optimize immune response.[21-23] The cellular defenses involving dendritic and T-cells produce Microbial, Pathogen- or Danger/damage-associated molecular patterns against organic (microbial pathogenic or nonpathogenic) or inorganic (nonmicrobial like surgery incision) insults respectively. These are dependent on the microbiome of the skin as well as the gut.[24] Besides being integral to organ-specific skin immunity against infection, the skin gut axis is integral to healthy gut microbiota. It has been studied that skin microbiome changes induce intestinal dysbiosis.[25] Intestinal dysbiosis triggers T cells and regulatory T lymphocytes (Treg) to increase systemic inflammatory response. Skin incision/injury alters colonic gene expression leading to overexpression of Regenerating Islet-derived protein 3 (Reg3) and Mucin 2 (Muc2), disrupting the gut microbiome and increasing bacterial penetration of the colonic mucosa.[25] Such skin insult-driven adverse events, lead to and precede the resultant decrease in intestinal immunity.[26] Similar immunity compromises can be induced by skin dysbiosis, in other organ systems besides intestines.[27] Like in the case of probiotic usage for gut dysbiosis, skin dysbiosis prevention, and restoration has been reported with the use of live biotherapeutic products (LBPs). Probiotic, a word from a Greek root meaning, prolife, coined by Parker in 1974, is an integral link in our co-existential chain.[8,28] These are widely distributed in our environment, plants and animals we live with, and food products.[8,13] While LBP being formulated in labs are required to undergo clinical trials to study their safety and efficacy, naturally occurring probiotics in traditional foods don’t need any such studies.[29,30] Topical probiotics, especially Lactobacillus species, have been extensively used in preventing and managing bacterial vaginosis, vulvovaginal, candidiasis, and sexually transmitted infections.[31-33] Not only probiotics from foods but also from soil bacteria have been used with encouraging results.[34] Dairy food products are good sources of lactobacillus, the same microbe that has been therapeutically used for topical application in LBPs.[35] Food fermentation is an upstream extension of food digestion and has been linked to health and prolonged lifespans. While various fermented food products have been studied for their benefits, Dahi, a fermented milk traditional preparation, has been reported as preferred source.[36] Dahi provides an harmless lactic acid bacteria, as well as many bioactive compounds and bacteria-derived metabolites produced during fermentation.[37] These products have an immune as well as significant antimicrobial activity against pathogens including Gram-positive and negative bacteria including Escherichia coli et al. Probiotics in fermented dairy have been reported to reduce the risk of sepsis, improve the symptomatic burden of HIV, reduce hepatitis C virus burden, and improve the resolution of Helicobacter pylori infections.[38] Besides these the natural fermented milk also contains bacteriophages. Bacteriophages are the most abundant living organisms on the planet, ten times the number of bacterial species, i.e., >10.[31] Bacteriophages are found as natural antimicrobials in Dahi and can selectively infect and kill food-borne pathogens while sparing the good microbiota. These bacteriophages are generally considered safe and directly or indirectly benefit the product with the growth of healthy microbiota.[39] The health benefits of Dahi have been realized for centuries in Indian civilization and put in practice for skin health. A bath or head wash with kitchen Dahi is a routine for traditional Indian families. Authorities have realized this and are advising to integrate of this traditional wisdom in healthcare delivery.[40,41] We have been advising our patients a head wash and bath after the application of Dahi, a night before surgery. On the day of surgery, standard protocols for asepsis, skin preparation, and chemoprophylaxis are followed. The results in terms of SSI and wound healing are encouraging. The beneficial results are a direct extension of benefits observed in our patients by substituting the modern recommendation of high-calorie preoperative drinks by traditional sweet Dahi, available in Indian kitchens as Lassi or Shrikhand.[41] This is truly putting in practice the scientific mind of Imagineer in practice. Dahi has emerged as an effective antidote probiotic against the skin microbiome dysbiosis that forms the fourth dimension of the Epidemiological Quad of SSIs. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.
Authors: Brij B. Agarwal, Palak Nayan Agarwal, Dhyan Pankaj Patel, Arathy R. Nair, Vikram Singh
Institution: Sir Ganga Ram Hospital
Language: English
Subfield: Surgery
Field: Medicine
Domain: Health Sciences
Open Access status: diamond
OpenAlex ID: W4411300266