S. thermophilus is an often encountered probiotic used in cheese and yogurt production. Although not particularly well studied as a probiotic, this bacterium has many potential health benefits. It is great for the skin, may alleviate GI symptoms, and may increase folate and hemoglobin levels.

What is Streptococcus thermophilus?

Streptococcus thermophilus is a thermophilic lactic acid bacterium traditionally and widely used as a starter in manufacturing dairy products such as cheese and yogurt.

At birth, S. thermophilus is among the first colonizers of the GI tract and may impact the maturation and homeostasis of the intestinal epithelium after birth (R).

Health benefits of S. thermophilus

1) S. thermophilus Reduces Lactose Intolerance

Along with L. delbrueckii ssp. bulgaricus, S. thermophilus improves lactose digestion in the gastrointestinal tract and reduces symptoms of lactose intolerance (R).

2) S. thermophilus Stimulates the Immune System

S. thermophilus exerts an anti-inflammatory effect by suppressing the Th17 response in mice white blood cells (R).

S. thermophilus stimulates macrophage and T-cell cytokine production (R).

S. thermophilus stimulates epithelial cell regeneration and immunological innate defense mechanisms (R).

3) S. thermophilus May Inhibit Antibiotic-Associated Diarrhea

Mice infected with C. difficile treated with viable S. thermophilus exhibited less weight loss, reduced diarrhea, and lower detectable toxin levels (R).

4) S. thermophilus May Improve Oral Health

S. thermophilus inhibits the growth of P. gingivalis, and reduced the emission of volatile sulfur compounds that can cause oral malodor (R).

5) S. thermophilus Stimulates the Growth of Other Probiotics

S. thermophilus is used in the production of yogurt alongside Lactobacillus delbrueckii ssp. bulgaricus. These two species are synergistic. S. thermophilus provides L. d. bulgaricus with folic and formic acid, while L. d. bulgaricus provides amino acids and peptides for the growth of S. thermophilus (R).

S. thermophilus improves the viability of L. brevis in milk (R).

6) S. thermophilus May Prevent Gastritis

Aspirin causes gastritis or stomach ulcers if intensively employed. S. thermophilus reduces inflammation and prevents chronic gastritis in aspirin-treated mice (R,R).

7) S. thermophilus May Improve Mucositis

In one study, S. thermophilus partially alleviated mucositis induced by administration of the antimetabolite chemotherapy drug methotrexate in rats (R), while in another study no protective effects were observed (R).

S. thermophilus partially prevented the loss of body weight induced by doxorubicin and slightly ameliorated doxorubicin-induced mucositis in rats (R).

S. thermophilus significantly reduced intestinal mucositis severity in rats treated with 5-Fluorouracil (R).

8) S. thermophilus May Ameliorate IBD

S. thermophilus increased hematocrit and hemoglobin concentrations, and improved acute colitis in mice (R).

S. thermophilus repressed the Th17 response and ameliorated intestinal lesions in mice with colitis (R).

9) S. thermophilus Can Increase Folate and Hemoglobin

Folate-rich fermented milk produced by high-folate-producing S. thermophilus increases hemoglobin levels in mice (R).

10) S. thermophilus is Beneficial for the Skin

Ceramides play an essential role in the barrier and water-holding functions of the healthy skin. A significant increase in skin ceramide levels was observed in healthy subjects after treatment with a cream containing a preparation of S. thermophilus (R).

Topical treatment with an S. thermophilus-containing cream increased ceramide levels and increased hydration in the skin of healthy elderly women (R).

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) (R).

11) S. thermophilus May Potentially Combat Cancer

Mice with fibrosarcoma, treated by S. thermophilus were protected against this tumor when re-challenged. Additionally, spleen T-lymphocytes from cured animals could effectively transfer the antitumor activity to recipients transplanted with the tumor (R).


  • S. thermophilus can increase (R) or decrease IFN-γ  (R,R).
  • S. thermophilus can increase (R,R) or decrease TNF-α (R).
  • S. thermophilus can increase (R,R) or decrease IL-6 (R).
  • S. thermophilus decreases IL-1β (R).
  • S. thermophilus increases IL-2, IL-5 (R), IL-8 (R) and IL-10 (R,R,R).
  • S. thermophilus decreases IL-17 and the number of Th17 cells (R,R).


S. thermophilus is widely used in the dairy industry and is considered safe for consumption.

However, probiotics should be avoided in immunocompromised individuals, people with organ failure, and dysfunctional gut barrier, where they may cause infection.

S. thermophilus can produce low amounts of biogenic amines histamine and tyramine (R).

Buy S. thermophilus

These probiotic products contain S. thermophilus:


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