Certain probiotics may reduce inflammation and symptoms of allergies, autoimmunity, rashes, and even complications from cancer treatments. How do they work, and which species are most beneficial? Learn more here.
Probiotics and Inflammatory Disease
Inflammation is one of the most complex and potentially dangerous mechanisms in the human body. When tightly controlled, it is important for healing and the immune response, but if it gets out of control, it can contribute to autoimmunity and tissue damage.
Many probiotic bacteria are under investigation for their apparent anti-inflammatory effects. In this post, we’ll explore the benefits that have been studied so far. Remember that probiotics may not be right for everyone; talk to your doctor before starting a new probiotic supplement.
Possibly Effective For
Supplementation with a synbiotic, which is a mixture of probiotic bacteria (in this case L. casei, L. rhamnosus, S. thermophilus, B. breve, L. acidophilus, B. longum, L. delbrueckii ssp. bulgaricus) and nutrients for the bacteria to feed on (in this case, fructo-oligosaccharides) reduced inflammation markers in adults .
B. longum ssp. infantis reduced proinflammatory markers in patients with ulcerative colitis, chronic fatigue syndrome, and psoriasis .
L. casei improved natural killer (NK) cell activity and produced a more anti-inflammatory cytokine profile in healthy non-immunocompromised elderly subjects .
L. paracasei significantly increased the release of pro-inflammatory cytokines and stimulated the innate immune system in human enterocytes and dendritic cells (DCs) .
L. delbrueckii ssp. lactis seems to have anti-inflammatory effects . Skimmed milk with L. delbrueckii ssp. bulgaricus inhibits the secretion of proinflammatory cytokines produced by accessory white blood cells .
L. acidophilus reduced inflammation in human intestinal epithelial cells .
B. animalis ssp. lactis added to yogurt post-fermentation was anti-inflammatory in healthy adults .
B. animalis ssp. lactis inhibited inflammation in elderly volunteers .
B. longum ssp. infantis suppressed proinflammatory IL-17 cytokine production and may be useful in the treatment of Th17-mediated diseases .
In one study, L. reuteri inhibited NF-κB, one of the most important factors in reducing whole-body inflammation .
See individual probiotic posts for animal studies and technical information.
L. salivarius decreased the secretion of proinflammatory cytokines and showed beneficial immunomodulatory activity in asthmatic subjects .
B. breve showed promising probiotic properties and beneficial immunomodulatory activity in allergic asthma .
C. butyricum improved asthma and serum specific IgE in the patients treated with specific immunotherapy (SIT), increased IL-10, and converted antigen-specific B cells to regulatory B cells .
Oral administration of L. rhamnosus attenuated the features of allergic asthma in mice [15, 16].
L. salivarius decreased allergen-induced airway response in mice . It also alleviated asthma symptoms like airway hyperreactivity and airway inflammation in mice .
L. gasseri attenuated allergen-induced airway inflammation and IL-17 pro-inflammatory immune response in mice with allergic asthma .
L. lactis significantly attenuated atopic esophageal and bronchoalveolar eosinophilic inflammation in mice .
B. breve had strong anti-inflammatory properties in asthmatic mice [21, 22, 23].
L. paracasei administration to mothers during gestation/lactation protected against airway inflammation in mice offspring .
B. longum attenuated allergic airway inflammation in mice .
B. bifidum significantly decreased airway hyperresponsiveness, decreased lung inflammation and lowered the Th2 response in allergic mice [26, 27].
3) Allergic Rhinitis
17 out of 22 trials in a review showed a significant benefit of probiotics clinically, whereas eight trials showed significant improvement in immunologic parameters in allergic rhinitis .
Citrus juice fermented by L. plantarum improved the symptoms of Japanese cedar pollinosis .
C. butyricum markedly enhanced the efficacy of SIT on allergic rhinitis in patients with allergies .
Co-administration of C. butyricum markedly enhanced the treatment of allergic rhinitis .
L. rhamnosus supplementation showed good clinical and immunologic response in children with allergic rhinitis .
Volunteers with seasonal allergic rhinitis treated with L. casei showed a significant reduction in levels of antigen-induced cytokines .
A significant reduction of nasal symptoms and improved quality of life were achieved in patients with Japanese cedar pollinosis, who received L. paracasei when pollen scattering was low. However, the effects were limited during the peak period .
At least five clinical studies with L. paracasei demonstrated clinically significant improvements in allergic rhinitis , while one did not .
Subjects with a medical history of allergic rhinitis to grass pollen that received L. paracasei-fermented milk had lower nasal congestion and less nasal itching .
In children with perennial allergic rhinitis, L. paracasei improved symptoms of sneezing, itchy nose, and swollen eyes .
L. paracasei improved the quality of life of subjects with persistent allergic rhinitis who were being treated with an oral H1-antihistamine. In this study, nasal symptoms did not change, but ocular symptoms consistently improved .
Heat-killed L. paracasei effectively improved the overall quality of life in patients with allergic rhinitis induced by house dust mite .
L. acidophilus alleviated allergic symptoms in patients with Japanese cedar pollinosis [39, 40].
L. acidophilus alleviated the symptoms in patients with perennial allergic rhinitis .
Heat-killed L. gasseri improved nasal symptoms and pollen-specific IgE levels in subjects with Japanese cedar pollinosis .
The addition of L. johnsonii to levocetirizine improved perennial allergic rhinitis in children .
Intake of yogurt or powder supplemented with B. longum alleviated subjective symptoms and affected blood markers of allergy in individuals with Japanese cedar pollinosis [44, 45, 46]. Nasal symptoms such as itching, rhinorrhea, and blockage, as well as throat symptoms, tended to be relieved with this probiotic .
B. animalis ssp. lactis improved nasal symptoms in subjects suffering from seasonal allergic rhinitis .
Check individual posts for more information and animal studies.
The combination of prenatal maternal (2 – 4 weeks) and postnatal pediatric (6 months) L. rhamnosus treatment in families with a history of atopic disease, significantly lowered the risk of eczema at the age of 2, 4 and 7 .
In infants receiving either L. rhamnosus or B. lactis after 2 months, eczema symptoms were significantly improved .
L. rhamnosus efficiently prevented the development of eczema and possibly also atopic sensitization in high-risk infants up to 6 years old .
Cumulative prevalence of eczema and the prevalence of rhinoconjunctivitis were significantly reduced in the children taking L. rhamnosus .
B. animalis ssp. lactis significantly improved eczema symptoms in infants .
When administered to pregnant women with a family history of allergic diseases, a mixture of B. bifidum, B. lactis, and L. acidophilus significantly lowered the prevalence and incidence of eczema in infants at high risk of allergy .
B. breve reduced the incidence of developing eczema and atopic sensitization in infants at high risk of allergic disease .
B. bifidum had a positive effect on the prevention and treatment of eczema in infants .
The use of multi-strain probiotics appeared to be most effective for eczema prevention .
5) Atopic Dermatitis
The use of L. rhamnosus by mothers lowered the risk of developing atopic dermatitis during the first 2 years of life .
L. rhamnosus decreased symptoms of atopic dermatitis after an 8-week treatment in children aged 4 – 48 months .
Daily intake of citrus juice containing heat-killed L. plantarum alleviated symptoms of atopic dermatitis in humans .
L. salivarius improved symptoms in children [60, 61] and adults with atopic dermatitis .
Heat-killed L. paracasei improved atopic dermatitis (AD) in adult patients .
Long-term oral administration of L. acidophilus restored Th1/Th2 balance and ameliorated the symptoms of atopic dermatitis in children .
Prolonged ingestion of L. acidophilus significantly decreased the eczema area and severity index in patients with adult atopic dermatitis [65, 66]. The probiotic also suppressed scratching behavior .
B. breve improved symptoms of atopic dermatitis in infants [67, 68].
Topical administration of an S. thermophilus-containing cream to patients with atopic dermatitis increased ceramide levels and improved the signs and symptoms of atopic dermatitis (i.e. erythema, scaling, pruritus) .
See individual probiotic posts for more information and animal studies.
Probiotics harmonized Th1/Th2 imbalance in allergic conditions in adults .
L. brevis suppressed systemic anaphylaxis  and inhibited IgE production and histamine secretion in allergic mice .
L. casei protected mice from acute allergic inflammation (anaphylaxis) .
Allergies in Newborns
Consumption of L. rhamnosus-fermented milk by mothers and offspring was associated with a reduction in physical allergic symptoms in newborn mice .
Neonatal mother-to-offspring colonization with B. longum reduced allergic responses in mice .
L. rhamnosus accelerated oral tolerance acquisition in cow’s milk allergic infants [75, 49].
L. rhamnosus decreased the allergic response to peanuts in children .
In one study of milk-hypersensitive adults, L. rhamnosus reduced the immunoinflammatory response .
L. plantarum reduced the allergenicity of soy flour .
L. salivarius, L. paracasei, B. animalis and B. bifidum prevented atopic sensitization to common food allergens. The authors of this study believe that this probiotic blend could thereby reduce the incidence of atopic eczema in early childhood .
L. delbrueckii ssp. bulgaricus degraded the allergenic whey protein β-lactoglobulin and inhibited IgE binding in allergic patients .
L. helveticus alone or in combination with S. thermophiles effectively reduced the antigenicity of α-lactalbumin and β-lactoglobulin, the major allergens in cow’s milk .
L. helveticus can significantly degrade the major allergens in propolis, including esters of caffeic acid .
L. fermentum degraded αS1-casein and lowered the recognition and the binding of this casein to IgE from the blood of patients with cow’s milk allergy .
B. breve improved symptoms of allergic hypersensitivity to cow’s milk in infants .
Oral mucositis is one of the most common, debilitating complications of cancer treatments, particularly chemotherapy and radiation. L. brevis reduced the incidence and severity of anticancer therapy-induced oral mucositis and improved the tolerance to chemo-radiotherapy, and anticancer treatment completion .
L. acidophilus improved inflammatory and functional aspects of intestinal mucositis caused by chemotherapy in mice .
S. boulardii reduced the inflammation and dysfunction of the gastrointestinal tract in mice with intestinal mucositis .
In one study, S. thermophilus partially alleviated mucositis induced by administration of the antimetabolite chemotherapy drug methotrexate in rats , while in another study no protective effects were observed .
S. thermophilus partially prevented the loss of body weight induced by doxorubicin and slightly ameliorated doxorubicin-induced mucositis in rats .
S. thermophilus significantly reduced intestinal mucositis severity in rats treated with 5-Fluorouracil .
S. cerevisiae reduced oxidative stress, prevented weight loss and intestinal lesions, and maintained the integrity of the mucosal barrier in mice with mucositis .
Insufficient Evidence For
The following purported benefits are only supported by limited, low-quality clinical studies. There is insufficient evidence to support the use of probiotics for any of the below-listed uses. Remember to speak with a doctor before taking probiotic supplements, and never use them in place of something your doctor recommends or prescribes.
8) Autoimmune Disorders
Some researchers believe that probiotics and prebiotics have the potential to curb the autoimmune response. They are being investigated as an alternative to detrimental immunosuppressive drugs .
L. johnsonii delayed or inhibited the onset of type 1 diabetes in diabetes-prone rats [92, 93].
Intestinal dysbiosis, characterized by a reduced Firmicutes/Bacteroidetes ratio, has been reported in systemic lupus erythematosus (SLE) patients . B. bifidum supplementation prevented CD4+ lymphocyte over-activation and may help in restoring the Treg/Th17/Th1 imbalance present in patients with SLE .
L. casei supplementation helped alleviate symptoms and improve inflammatory cytokines in women with rheumatoid arthritis .
A mix of L. acidophilus, L. casei and B. bifidum improved rheumatoid arthritis, decreased insulin levels, and improved total- and low-density lipoprotein cholesterol levels .
Adjunctive treatment with B. coagulans was safe and effective for patients suffering from rheumatoid arthritis. B. coagulans improved pain, improved self-assessed disability, and reduced CRP levels. It also was associated with improved ability to walk 2 miles, reach for objects, and participate in daily activities .
L. casei protected mice from autoimmune arthritis . Consumption of L. casei prior to infection prevented the intestinal and joint inflammation triggered by Salmonella in mice .
L. casei reduced pain, inflammatory responses, and articular cartilage degradation in arthritic mice. L. casei together with glucosamine decreased expression of various pro-inflammatory cytokines and matrix metalloproteinases, while up-regulating anti-inflammatory cytokines .
Similarly, L. casei effectively suppressed symptoms of rheumatoid arthritis in rats: the symptoms that saw improvement included paw swelling, lymphocyte infiltration, and destruction of cartilage tissues. Anti-inflammatory cytokines were increased, while pro-inflammatory cytokines were decreased [100, 101, 102].
Oral intake of skimmed milk fermented with L. delbrueckii ssp. bulgaricus markedly inhibited the development of arthritis in mice .
L. acidophilus decreased arthritis symptoms and maintained normal histology of reproductive organs in rats .
L. acidophilus showed effects comparable to the drug indomethacin in decreasing organ damage associated with arthritis in rats. This probiotic down-regulated pro-inflammatory and up-regulated anti-inflammatory cytokines .
L. helveticus strongly alleviated symptoms of arthritis in mice .
B. coagulans significantly inhibited fibrinogen (Fn), blood amyloid A, and pro-inflammatory cytokine production in arthritic rats .
10) Celiac Disease
B. longum ssp. infantis reduced gastrointestinal symptoms in untreated Celiac disease (CD) patients .
B. longum improved gut microbiota composition and immune parameters in children with newly diagnosed CD .
Oral administration of B. longum ameliorated gliadin (gluten)-mediated perturbations in liver iron deposition and mobilization in rats with CD .
B. longum attenuated the production of inflammatory cytokines and the CD4+ T-cell mediated immune response and protected newborn rats against gliadin (gluten)-induced enteropathy .
B. breve decreased the production of the pro-inflammatory cytokine TNF-α in children with Celiac disease on a gluten-free diet .
Some researchers think that live B. animalis ssp. lactis bacteria may directly counteract the harmful effects exerted by celiac-toxic gluten (gliadin) to human intestinal cells .
L. casei induced complete recovery in mice with enteropathy such as Coeliac disease .
Animal & Cell Research (Lacking Evidence)
No clinical evidence supports the use of probiotics for any of the conditions listed in this section. Below is a summary of the existing animal and cell-based research, which should guide further investigational efforts. However, the studies listed below should not be interpreted as supportive of any health benefit.
11) Lung Injury and Inflammation
B. longum treatment significantly improved lung injury following infection and sepsis in mice. This probiotic also decreased lung inflammatory responses .
Certain probiotic supplements have successfully reduced inflammation and symptoms of a variety of inflammatory conditions. These include allergies, autoimmunity, rashes, and complications from cancer treatments. Probiotics aren’t for everyone, and their interactions with the immune system may be troublesome to some people. Remember to talk to your doctor before starting a new probiotic.
We’ve compiled deep dives into each potential benefit of probiotics. Check them out here: