Antibiotic (AB) microbial resistance (AMR), a growing international public health problem, demands global strategies for its control and mitigation. AMR’s impacts include greater mortality, morbidity, and economic costs and losses. Formal policies adopted until the date of this review do not focus on the potential of complementary and alternative medicine (CAM) to reduce or delay antibiotic use. Non-AB treatments being studied for symptom relief and/or reducing infection include immune stimulation, phage therapy, antibodies, lysins, probiotics, and peptides. European observational studies show that CAM practices and hospitals may have lower AB prescription rates than conventional practices and hospitals; this may reflect patient self-selection of CAM.
The mostly Europe-based authors of this narrative review set out to describe differences in worldview between CAM and conventional medicine (CM) that may be relevant in preventing and treating infections and in combating AMR; potential contributions of CAM in reducing AB use; and evidence that supports such contributions as well as the safety of CAM prevention and treatment strategies. This first, broad review lays the groundwork for more rigorous scoping reviews and/or systematic reviews (SRs) on subareas of the emerging field of natural prevention and treatment of infections and the reduction of AMR. They searched three major electronic databases using specific, limited search terms and consulted CAM research experts individually and/or convened in workshops. Studies selected focused on CAM or integrative medicine (IM) and covered worldview, health promotion (wellness) concepts, AB prescription or use, or prevention or treatment of infection. Studies on conventional prevention or treatment strategies alone or the use of CAM/IM for noninfective conditions were excluded. Of 516 studies located in database searches and 147 identified by other sources, 18 were duplicates, and 355 were excluded on the basis of title or abstract. Of 290 assessed in full-text, 78 did not meet review criteria; 212 were included. Of these, 15 concerned worldview; six, wellness; nine, AB prescription/use; 51, prevention of infection; and 131, treatment.
Worldview differences between CAM and CM can be sharp; most broadly, CAM seeks to restore and preserve homeostasis as the best prevention and treatment strategy, while CM seeks to rid patients of disease-causing organisms. Both, however, view health as the default condition of human beings. Illness indicates that an imbalance has occurred in healthy physiological processes, caused or exacerbated, or taken advantage of, by opportunistic organisms. CM’s main treatment strategy for infection is pharmacological antimicrobial treatment; CAM’s, support for the organism’s self-regulation of physiological functions needed to overcome infection through nonpharmaceutical means. Differences between CAM and CM are diminishing as a variety of factors emerge favoring IM, combining the best CM and CAM practices.
CAM disease prevention strategies center on reducing stress, insomnia, depression, and/or anxiety (all associated with greater susceptibility to infection); promoting a healthy diet and physical exercise (both reducing risks of infection); supporting the fever reaction of healthy organisms, and preventing infection with natural agents. The evidence available supports the adoption of a rhythmic, balanced lifestyle, frequently urged in CAM for general physiological resilience. Meditation is used to reduce sequelae of psychological stress; mindfulness; to reduce symptoms of stress, anxiety, and depression. Education in systems that use biorhythms in curriculum design, including the Steiner and Waldorf schools, is associated with lower serum cortisol levels, fewer symptoms of anxiety and depression, and psychosocial benefits in students compared with those educated in conventional schools. Many foods improve immunity. Dietary changes can cause rapid changes in the gut microbiome, a principal regulator of innate immunity. Probiotics, prebiotics, and polyphenols are used to modulate the composition and/or activity of the microbiota.
The authors selected 12 Cochrane reviews (CRs), 16 non-Cochrane reviews (NCRs), 15 clinical studies (CSS), and 20 studies on traditional use and in vitro reports to survey the evidence for effects of CAM treatment strategies. SRs, categorized by indication, included seven CRs and 13 NCRs on respiratory infections, two CRs and one NCR on UTIs, and three CRs on other infections. Two NCRs on AB-associated diarrhea were included. CSS included two observational studies on acute respiratory and ear infections, one RCT and one observational study on otitis media, four RCTs on infected wounds and methicillin-resistant Staphylococcus aureus (MRSA), and seven RCTs and an observational study on other infections. Both CRs and NCRs reported that CAM treatments for respiratory infections are promising; some have been found efficacious in SRs. CAM strategies for UTIs in adult women and skin infections are promising, but a more rigorous study is needed. For UTIs, for example, 22 relevant articles including three SRs, two SRs with MA, eight RCTs, five NCRs, and four sets of clinical guidelines reach different findings for cranberry (Vaccinium macrocarpon, Ericaceae) products.
Many CSS investigated CAM treatments that have not been subjects of SRs. An international, multicenter cohort study found that homeopathy was not inferior to CM in acute respiratory or ear infections, with a significantly faster onset of improvement in adults and children, and fewer AEs in the homeopathy group. In a prospective observational study, children with acute respiratory or ear infections who received anthroposophical medicine (AM) used fewer ABs, analgesics, and antipyretics; had somewhat faster symptom relief; and greater caregiver satisfaction than those who received CM. Juzen-taiho-to, a Japanese Kampo herbal medicine, was found effective in preventing recurrent acute otitis media in children; with significantly less AB use seen when used integratively with AM in children with chronic otitis media.
Other potentially valuable CAM treatments have not been clinically studied, or not for infections, but have long traditions and/or in vitro support for their activities. The need for anti-ABR agents and strategies demands their investigation. The authors cite only a few CAM anti-infectives. In comparison, a review named 255 (70% of 365 reviewed) plants with antimycobacterial activity. Protocatechuic acid, found in many food plants, has antimicrobial effects and acts synergistically with some ABs against resistant pathogens. Other CAMs also have some evidence of efficacy in infections. Acupuncture may reduce the pain of acute sore throat. Blue light is bactericidal in vitro and in vivo. AM practice-based evidence supports the external application of essential oils for symptom relief.
AB AEs include diarrhea, candidiasis, obesity (linked with infant AB use), allergies, and increased incidence of irritable bowel syndrome and irritable bowel disease. In children with acute otitis media given ABs, one in 14 experienced AEs that would not have occurred had ABs been withheld. AEs of herbs are overall modest and mild, but a few are associated with severe AEs. Poor knowledge of herbs’ mechanism(s) of action, contraindications, potential AEs, and interactions with existing drugs and/or foods presents concerns. AEs involving homeopathic or AM formulas are infrequent and usually mild to moderate, with anaphylactic reactions very rare.
The authors did not formally rate the quality of evidence for CAMs mentioned but note that it was often low. The lack of high-quality evidence and consistent results are prime barriers to acceptance of CAM strategies to combat infection and ABR. Others include ongoing worldview clashes between CAM and CM, concerns about CAM product quality and/or safety, and concerns involving cultivation and manufacturing practices and potentially inappropriate use. Poor physician and patient education, regulatory barriers to CAM research, and methodological difficulties in evaluating CAMs, especially multi-herb formulas, in ways comparable to those used for single-compound CM drugs also limit CAM’s anti-infective application. Where RCTs have been performed, they may give false-negative results due to the lack of individualization, a key factor in many CAM practices. Much work remains to make CAM’s anti-infective strategies widely useful in combating disease and ABR. The authors enumerate several of these broad research goals.
Baars EW, Belt-van-Zoen E, Breitkreuz T, et al. The contribution of complementary and alternative medicine to reduce antibiotic use: a narrative review of health concepts, prevention, and treatment strategies. Evid Based Complement Alternat Med. February 2019;2019:5365608. DOI: 10.1155/2019/5365608.