This study aims to explore the efficacy and safety of a synbiotic formula (BLHK03) in alleviating chemotherapy-induced alopecia (CIA) in breast cancer patients and the compositional and functional changes in the gut microbiome of breast cancer patients undergoing chemotherapy and treatment with BLHK03.

In a mice study, it was shown that oral administration of a probiotic isolated from healthy faeces, B. longum HK003, has protective effects against alopecia related to chemotherapy. Mice were treated with 100 mg/kg cyclophosphamide (CYP) once monthly, for 4 months. The CYP-treated mice were then treated with B. longum HK003 for 14 days. Results showed that B. longum treatment significantly enhanced skin thickness histologically. In the subcutis, the quantity and size of anagen follicles were increased, whilst the quantity of atrophic follicles were decreased.

Currently, there is no documentation of potential probiotic-drug interactions in breast cancer patients undergoing chemotherapy. A previous randomized controlled trial reported no adverse event associated with the use of synbiotics in breast cancer patients during the treatment period(9). Beneficial effects on chemotherapy-induced fatigue and abnormal stool consistency were also observed in subjects receiving synbiotics(9).

Biotin is a water-soluble vitamin that is naturally present in some food and available as a dietary supplement for healthy hair and nails due to its role in keratin production. Most healthy individuals achieve adequate intake of biotin through a well-balanced diet. Current recommendation for biotin by the Food and Nutrition Board (FNB) at the National Academies of Sciences, Engineering, and Medicine stated that the daily adequate intake (AI) for adults is 30 mcg/day. Although biotin has been widely used as dietary supplement, data on the actual benefit of its effect on hair growth is limited(10).

The use of B. longum HK003 in alleviating chemotherapy-induced alopecia in breast cancer patients has not been explored. This pilot, double-blind, randomised, placebo-controlled trial aims to explore on the efficacy and safety of a synbiotic formula (BLHK03) in alleviating chemotherapy-induced alopecia (CIA) in breast cancer patients.

Inclusion Criteria:

• Females aged between 18 and 60 years who are newly diagnosed with stage I, II or III breast cancer
• Planned chemotherapy including an anthracycline or taxane to be completed within 6 months
• Mentally capable to participate in the study and provide informed consent

Exclusion Criteria:

• Pre-existing female-pattern baldness resembling picture I-3 or higher on the Savin scale at baseline
• History of hair transplantation, psoriasis or severe scalp infection
• Undergoing or plan to receive scalp cooling
• Plan for immunotherapy
• Known pregnancy or lactating
• Severe cardiac, hepatic, renal, pulmonary and haematic lesions or other life-threatening conditions
• Use of antibiotics, probiotics or prebiotics one month prior to enrolment
• No other alternative or complementary treatment for the cancer condition that may affect the gut microbiome analysis
• History of allergy to probiotics or lactose
• History of chemotherapy for other conditions

Attending physicians, investigators performing assessments in clinic visits and study participants will be blinded to the group allocation until study completion.