Complementary and alternative medicine is a growing area of research in inflammatory bowel disease (IBD). While it is clear that patients with IBD should take calcium and vitamin D supplements to prevent osteoporosis, the role of dietary and herbal supplements to treat the inflammation in IBD is still under investigation. Scientific studies have shown that probiotics are effective in treating pouchitis and ulcerative colitis. In addition to probiotics, prebiotics, omega-3 fatty acids, herbal supplements, and helminth (worm) therapy are examples of alternative treatments that are being studied. We are still learning about their treatment potential, as well as possible side effects.

Complementary and alternative medicine continues to grow in popularity and is being utilized with increasing frequency among inflammatory bowel disease (IBD) patients [1]. Despite its popularity, the evidence to support dietary therapy, probiotics, and alternative therapy in patients with IBD is limited. Some studies suggest a potential therapeutic effect of these therapies; however, the scientific rigor of these studies varies greatly. Concomitant IBD therapy, disease severity, duration, phenotype, and patient demographics are among several possible confounders that are often not adjusted for in the observational investigations. Focusing specifically on existing randomized trials, data for curcumin and helminth therapy is the strongest to suggest a potential treatment benefit. Conversely, data are weak to support the use of aloe vera, dietary fish oil, or Boswellia as IBD therapy. There is good evidence that probiotics, specifically VSL#3, prevent the first and recurrent episodes of pouchitis and treat active pouchitis and ulcerative colitis [2].

Choosing the right treatment for IBD can be a complicated endeavor. Fortunately, many treatment options have emerged in the past several decades; thus, we are no longer limited to steroids as the only available, effective medical therapy to treat IBD. Newer steroid-sparing agents, including immunosuppressant and biologic therapies, have shown efficacy in clinical trials in both inducing and maintaining remission in IBD. That said, the costs of these therapies can be prohibitive, especially with long-term use, and they are not without their own set of undesirable side effects, including but not limited to an increased risk of infection, hepatotoxicity, bone marrow suppression, and malignancy. While these risks are low, and typically are outweighed by the benefits of therapy, patients and physicians alike would welcome effective treatment options that do not carry these risks.

Although not used specifically to treat IBD, vitamin and mineral supplements are used often by patients. Since vitamin and mineral deficiencies may be a result of the inflammatory process, reevaluation of the need for supplementation after the inflammation has been controlled and the symptoms have abated is reasonable. Low bone mass occurs in 18–42 % of IBD patients [3]. Steroid exposure increases this risk; however, osteoporosis has also been noted to occur more frequently even in steroid-naïve patients with IBD compared to matched controls [4], suggesting the inflammatory process itself confers additional risk, independent of steroid use. Such patients should be treated with calcium and vitamin D supplementation, typically under the guidance of an endocrinologist or rheumatologist.

To date, data are conflicting on the benefit of elemental nutrition in IBD. A prospective pilot study reported improvement in clinical symptoms, endoscopic scores, histopathology, and inflammatory cytokines in 28 patients with CD given an enteric elemental diet [5]. Some participants experienced diarrhea and abdominal colic, but, there were no instances in which the side effects required interruption of therapy. Occasionally antidiarrheals were also utilized. After 4 weeks of elemental diet, 71 % of patients achieved clinical remission. Endoscopic and histologic improvement was also demonstrated. Among those with endoscopic healing, previously elevated inflammatory cytokines were reduced to levels equivalent to healthy controls [5]. Elemental diets have not proven superior to standard medical therapy, as was reported in a meta-analysis reviewing trials that compared elemental diets to steroids [6].

It has been long suspected that gut microbiota plays an important role in the pathogenesis of IBD, though we are still learning about the complex interplay between diet, the gut microbiome, and the interaction with the host immune system. Prebiotics and probiotics have been studied as potential therapies that treat IBD by altering the intestinal bacterial milieu. Prebiotics are nondigestible carbohydrates, which yield a lower intestinal pH, favoring certain bacterial populations and theoretically helping to treat IBD. In a small study of ten patients with UC, the use of butyrate enemas decreased bowel movement frequency and bleeding and induced mucosal healing when compared to placebo [7]. Another study utilized oral ingestion of germinated barley with standard therapy to yield improved maintenance of remission in patients with UC [8]. Probiotics, which are strains of favorable intestinal microorganisms such as Lactobacillus and Saccharomyces, are recognized as effective therapy for antibiotic-induced diarrhea [9] and recurrent C. difficile infection [10], and in the IBD population they are best utilized in the treatment of pouchitis and ulcerative colitis [11, 12]. The data for VSL#3 in the treatment of pouchitis is strong and in a randomized trial was associated with 85 % of treated patients maintaining remission compared to only 6 % in the placebo group (p < 0.0001) [13]. VSL#3 has been evaluated in five studies in patients with ulcerative colitis. A meta-analysis of these studies reported a response rate of 53 % and a remission rate of 44 % in VSL#3-treated patients compared to 29 and 25 % of placebo-treated patients [2]. Outcomes for data on the use of probiotics in CD are less impressive. A recently published double-blinded, placebo-controlled trial compared maintenance of remission in CD patients treated with Saccharomyces boulardii or placebo and found no significant difference between the treatment groups [14]. Several meta-analyses failed to demonstrate a beneficial effect of probiotics in maintenance of remission or prevention of postoperative recurrence of CD [15–17]. Further investigation on the use of prebiotics, probiotics, and synbiotics (the combined use of pre- and probiotics) is needed to more definitively clarify their role in IBD therapy.

Many other alternative therapies believed to possess anti-inflammatory qualities have been investigated as possible treatment for IBD, such as aloe vera, fish oil, curcumin, marijuana, helminths, and Boswellia serrata. In vitro studies have demonstrated that aloe vera reduces inflammation in rat models of colitis [18], as well as in human colonic mucosa [19]. In clinical studies, a randomized, double-blinded, placebo-controlled trial demonstrated a trend toward symptom remission and response in UC patients given dietary aloe supplementation [20]. After 4 weeks of oral aloe vera gel supplementation, 30 and 47 % of the patients in the aloe vera group achieved clinical remission or response, respectively, compared to only 1 % remission and 1 % response in the placebo group. Mucosal healing was not significantly different between treatment arms.

Omega-3 fatty acids are well known for their anti-inflammatory effects and can be found in several dietary sources including fish oil, walnuts, flaxseed oil, and olive oil. These essential fatty acids have demonstrated beneficial effects in multiple pro-inflammatory conditions such as cardiovascular disease and rheumatoid arthritis [21] and consequently may be candidates for therapy in IBD. Dietary fish oils have demonstrated positive effects in rat models of colitis [22]. In CD, two large randomized trials reported no difference in relapse rates between patients treated with 4 g/day of omega-3 fatty acids compared to placebo [23]. A recently published systematic review compiling data from randomized trials performed in UC and CD demonstrated no effect with dietary fish oil supplementation [24].

Curcumin, a natural food additive known as turmeric, has also been described to exhibit anti-inflammatory effects in cell culture and animal studies [25]. In IBD, a small open-label pilot study evaluated the effects of curcumin as adjunctive therapy in five patients with ulcerative proctitis and five patients with CD [26]. Patients were allowed to continue existing therapy at entry including aminosalicylates, mercaptopurine, and budesonide. All patients but one (who discontinued the medication due to worsening fistula output) exhibited improvement in clinical symptoms and endoscopic scores. In a double-blinded, placebo-controlled trial, curcumin therapy resulted in decreased relapse rates in UC [27], and a recently published Cochrane systematic review deemed curcumin as safe and effective adjunctive therapy in UC [28].

Cannabis was recently studied in a prospective trial as induction therapy for CD [29]. Interestingly, patients included in this study had symptoms that were refractory to steroids, immunomodulators, or antitumor necrosis factor-α agents. After 8 weeks of cannabis therapy administered via cigarettes, clinical remission rates were higher in the cannabis compared to placebo group (45 % vs. 10 %, p = 0.43), and 90 % of those who received cannabis experienced a clinical response, compared to 40 % in the placebo group (p = 0.028). No changes in quantitative c reactive protein were noted in either treatment group, raising the question of whether cannabis decreases inflammation or only treats symptoms. There are obvious issues related to the use of cannabis in the treatment of IBD such as the fact that it is still illegal under Federal law and that chronic cannabis use is associated with a risk of significant cognitive, neuromuscular, and respiratory side effects [30]. Additional studies are needed to confirm the effectiveness of cannabis in the treatment of IBD and to evaluate if other delivery systems (oral intake) are efficacious.