B420 Probiotic

This is the all-rounder of the probiotic shelf rather than a specialist. Our naturopaths reach for it when toughness and a tested dose matter more than matching a bacterium to a stage of life.

A good fit if

• You want a shelf-stable product for travel, work or warm weather, and want the strain to hold up regardless
• You're an adult comparing products and would rather match a dose that's actually been tested than go for the biggest number
• You want the strain code printed on the panel so you can check the research behind it
• You're generally well, with a healthy immune system and no medical lines or catheters

Check with us first if

• You're pregnant or breastfeeding. Read the label, because some probiotics carry a warning against use while pregnant or breastfeeding.
• You're buying for a child. Many Australian probiotics carry an age limit on the label, and some aren't allowed under two at all.
• You have a severe dairy allergy. This bacterium is grown in, and often carried in, dairy-based ingredients, so the other ingredients matter as much as the bacterium.
• You have small intestinal bacterial overgrowth (SIBO), or symptoms that get worse with fermentable foods.
• You have short bowel syndrome, an ileostomy or colostomy, or inflammatory bowel disease.
• You're taking antibiotics, medicines that suppress or change your immune system, or any regular prescription medicine.

• HN019 (sold as HOWARU Bifido). Best known for: The research on dose and whole-gut transit time (how long food takes to pass through), and on everyday digestive symptoms in adults. Absorption: Shelf-stable. Studied at 1.8 billion and 17.2 billion CFU a day, and the higher dose did better. Typical use: Australian adult blends often list 2 billion CFU of HN019 alongside other strains.
• BB-12. Best known for: The most widely studied strain of this subspecies, and the one you'll most often find in yoghurt. Absorption: Comes in both shelf-stable and refrigerated versions, and is often paired with a Lactobacillus strain. Typical use: Around 5 billion CFU per serve in Australian children's powders, often with L. rhamnosus GG.
• Bi-07 and Bl-04. Best known for: The bulk strains in adult multi-strain capsules, usually making up most of the headline count. Absorption: Chosen partly because they hold up well in manufacturing for products that don't need a fridge. Typical use: Often 7 billion CFU each in a 30 billion CFU once-a-day capsule.
• B420. Best known for: A separate strain with its own research, unrelated to the transit-time studies. Absorption: Shelf-stable, and usually sold on its own rather than in a blend. Typical use: Results from the transit-time strains don't apply to it, and the reverse is also true.
• 'Bifidobacterium lactis' with no strain code. Best known for: You can't check it. The name alone can't be matched to any published research. Absorption: Impossible to know, because the organism isn't identified beyond subspecies. Typical use: Common on Australian labels, because no rule requires the strain to be listed.
• In yoghurt and fermented milk. Best known for: Where this subspecies was first found, and how most people first come across it. Absorption: How many survive depends on storage and shelf life, and counts are rarely shown on the tub. Typical use: A good food habit, but not a way to get a named strain at a studied amount.

Reference values. None. The NHMRC's recommended intakes cover nutrients, and a live bacterium isn't a nutrient. There's no recommended daily intake and no such thing as being low in B. lactis.

Typical supplemental range. This is one of the few probiotics where research has compared doses rather than testing just one. The adult study used two doses of HN019 for 14 days, 1.8 billion and 17.2 billion CFU a day. Both changed the result being measured, and the higher dose changed it more. Australian labels cover that whole range: 2 billion CFU of HN019 in an adult blend, 5 billion CFU of BB-12 in a children's powder, and 7 billion CFU each of Bi-07 and Bl-04 in a one-a-day capsule are all on shelves now.

Upper level. There's no NHMRC upper limit, and Australia's permitted ingredients list (Schedule 1) sets no maximum daily dose for it (item 873) or for any of the related B. animalis entries. That's simply how this kind of ingredient is regulated here, not a finding about safety.

Worth knowing. The dose comparison is what makes this bacterium worth its own page, and it also needs the most careful reading. It was measured over 14 days in 100 adults, using one strain, by researchers funded by that strain's maker. It doesn't mean more billions are always better. The result belongs to HN019 and to what that study measured. What you need depends on your age, diet and health, so talk to one of our naturopaths.

Food first, where the diet allows it.

• Yoghurt with added Bifidobacterium cultures: the most common dietary route; BB-12 is the strain most often added, and counts are seldom declared
• Fermented milk drinks and cultured dairy: where the subspecies was first isolated in 1997; present only where deliberately added, not as a starter culture
• Kefir: carries a broad mix of bacteria and yeasts, but not this subspecies at any declared or reliable level
• Fermented vegetables such as sauerkraut and kimchi: dominated by lactic acid bacteria from plants; bifidobacteria are not characteristic organisms of these ferments
• Any food at all: no food supplies a named strain such as HN019, BB-12, Bi-07 or Bl-04. A strain code exists only on a supplement

If any of these sound like you, talk to one of our naturopaths or your doctor before you start.

• A severely weakened immune system, including neutropenia (low white cells), active chemotherapy or immune-suppressing medicine after a transplant. Live organisms need specialist approval.
• Central venous catheters and other long-term lines, critical illness and intensive care. Check with your medical team first.
• An existing or suspected bloodstream infection. Check with your doctor first.
• Pregnancy and breastfeeding. Some probiotic products carry a warning against use, so read the label.
• Children. Many Australian probiotic products have an age limit, and some aren't allowed under two years.
• Severe dairy allergy. This subspecies is linked to dairy, and dairy-based carriers are common.
• Small intestinal bacterial overgrowth (SIBO), or symptoms that get worse with fermentable foods.
• Short bowel syndrome, an ileostomy or colostomy, or inflammatory bowel disease.
• Antibiotics, immunosuppressants and immune-modulating medicines. It's worth checking timing and whether it suits you.
• Bloating, wind or tummy discomfort that lasts beyond the first week or two.
• Fever, chills or feeling unexpectedly worse while taking it. Stop and get medical advice promptly.
• Assuming a label reading 'Bifidobacterium lactis' means a researched strain. Australian labels don't have to declare the strain.
• If you take prescription medicines, check with your doctor, pharmacist or one of our naturopaths before you start.