This clinical trial evaluates whether engineering gut microbiome using probiotics will alter the body's immune system to react to stage I-III breast or lung cancers that can be removed by surgery (operable). Having diverse species of bacteria inside the bowel may help improve the immune system, particularly the ability of the immune system to recognize cancer. Taking probiotics may change the diversity and make up of the bacteria in the bowels, and change how the immune system reacts to breast or lung cancer.

PRIMARY OBJECTIVES:

I. To conduct a pilot study of probiotics prior to surgery in operable breast and lung cancer patients.

II. To evaluate systemic and intratumoral immunomodulatory effects of probiotics in operable breast and lung cancer patients.

OUTLINE:

Patients undergo collection of blood samples at baseline and time of surgery, and collection of stool samples at baseline and after completion of probiotic regimen. Patients receive probiotics orally (PO) once on day 1, and then twice daily (BID) or three times daily (TID) for 2-4 weeks before standard of care surgery. Patients also undergo collection of tissue samples during standard of care surgery.

Inclusion Criteria:

• >= 18 years of age
• Histologically confirmed adenocarcinoma of the breast operable stage I-III or histologically confirmed carcinoma of the lung operable stage I-III will be enrolled prior to their definitive surgery
• Patients must have adequate organ function
• Patients must be willing to provide tissue, blood and stool samples for the research study

Exclusion Criteria:

• Patients must not receive systemic neoadjuvant therapy
• Patients must not have taken any probiotics in the past 30 days prior to the enrollment
• Patients with autoimmune disease, immune deficiency such as human immunodeficiency virus (HIV), irritable bowel, known diverticulosis, and other serious gastrointestinal (GI) conditions at treating physician's discretion will be excluded