Question: what vitamin is produced by bacteria in the gut
[{'answer': 'vitamin B', 'provenance': [{'wikipedia_id': '3135637', 'title': 'Human gastrointestinal microbiota', 'start_paragraph_id': 4, 'start_character': 384, 'end_paragraph_id': 4, 'end_character': 393, 'bleu_score': 1.0, 'section': 'Section::::Overview.\n'}]}, {'provenance': [{'wikipedia_id': '3135637', 'title': 'Human gastrointestinal microbiota', 'start_paragraph_id': 4, 'start_character': 0, 'end_paragraph_id': 4, 'end_character': 736, 'bleu_score': 0.9612260133949071, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 7869490130680120503}, 'section': 'Section::::Overview.\n'}]}]