Patients with various malignancies who are taken up for high dose chemotherapy followed by stem cell transplant (blood and marrow transplant) have very high chances of developing severe oral mucositis (between 95-100%). This mucositis not only causes significant morbidity but also hampers quality of life so much so that patients at times feel difficult to continue treatment.

No definite treatment exists for prevention or treatment of oral mucositis in this group of patients. Though one study has suggested that use of IV palifermin (a keratinocyte growth factor) will reduce duration and severity. Palifermin is very expensive and not available in country. Recently the investigators have shown effectiveness of a probiotic Lactobacillus CD 2 in reducing incidence and severity of chemo-radiotherapy induced mucositis in head and neck squamous cell cancer patients. (Published online in European Journal of Cancer: http://dx.doi.org/10.1016/j.ejca.2011.06.010). No significant toxicity has been reported with its use.

Now, the investigators want to study the efficacy of this drug to reduce severity of mucositis in patients undergoing hematopoietic stem cell transplantation. The drug will be supplied by CD Pharma India Private Limited.

The investigators further give undertaking that study will be carried as per good clinical practices (GCP) and declaration of Helsinki.

Inclusion Criteria:

1. Age between 10 and 70 years.
2. Karnofsky Performance Score ≥ 70%.
3. Confirmed histological diagnosis of cancer/leukaemia for which haematopoietic stem cell transplantation is an approved modality of therapy.
4. Patients eligible to receive high-dose chemotherapy as part of conditioning regime.
5. Concomitant co morbid condition if present, controlled by medicines.
6. Serum creatinine 1.8mg/dl.
7. Total bilirubin 2mg/dl.
8. Liver enzymes within three times of normal limit.
9. Expected survival > 6 months.

Exclusion Criteria:

1. Pregnant women and lactating mothers.
2. Patients with history of AIDS
3. Patients who have taken any other investigational product in last 4 weeks.
4. Patients having untreated symptomatic dental infection.
5. Patients with WHO Grade 3 or 4 oral Mucositis.
6. Other serious concurrent illness.
7. Inconclusive histological diagnosis.
8. Patients on anticancer antibiotics.
9. Patients with signs and symptoms of systemic infections.
10. Patient's/guardian's refusal to sign informed consent.