Yes, chlorella helps Body Odor in general.
when it comes to bad breath a combination of zinc supplement (30-50 mg daily)and vit B + either chlorella or barley grass powder (or similar green powders) should help within a month or two.
Zinc / vit B helped my teeenager`s bad breath, together with Iodine etc. The vit B is for the uptake of zinc, and also helping the digestion in general.
"Instead of bacteria binding to surface proteins and releasing sulfur gases, available zinc ions bind to protein receptors, disallowing new sulfur gas from being created. Zinc ion technology offers a long-term solution for bad breath."