This includes sticks, rocks, dirt and sand as well as licking "unsanitised shopping carts".
"I do not fear bacteria. In fact, I welcome it. I trust nature and my baby. It is not a coincidence babies have this instinct while they are breastfeeding," she said in a controversial video that has been viewed 12.6 million times.
From around three months, babies use their mouths to explore the world around them, a phase known as "baby mouthing".
While consuming a small amount of bacteria from the objects babies put in their mouths can help "boost immune systems", sand and dirt is known to host dangerously high levels of bacteria and can cause breathing problems when inhaled.
As a result, Alice's post sparked a huge debate among parents as to whether or not the move was as beneficial for her son's health as she believed.
"I get where you're coming from, but also parasites, flesh-eating bacteria, meningitis, measles, MRSA etc..." one woman wrote.
US mum Alice Bender has opened up about why she lets her baby eat sand and chew rocks. Photo / Instagram
"It's one thing letting your child eat food off the ground, but you're taking it too far," another said.
"I do understand the bacteria thing but sand and sticks doesn't sound right.
Others argued they had been allowed to eat dirt as a child and had grown up "fine".
"I find it so weird when people shield their kids from everything," one woman argued.
"Your baby is going to have an amazing immune system," another claimed.
However, lots thought the video had to be a "joke" because of its extreme views.
"This is a joke right?" one asked.
The baby is also is allowed to chew on the straps and handles of unsanitised shopping trolleys. Photo / Tik Tok
"How are people agreeing with this?" another stated.
It's not the first parenting video Alice has shared with her 275,000 followers that has raised eyebrows. The mother has previously opened up about her home birth story, revealing she gave birth "peacefully" in her bathroom with no medical assistance.
She's also revealed she goes "dumpster diving" for food, doesn't believe in vaccinations going against all medical advice and doesn't have a relationship with her family over her views on veganism.
The mum, who also has a daughter older than Fern, also said she has never used SPF on her children, a move fiercely condemned by experts. Sunscreen helps protect against skin cancer, according to Cancer Council. It should be applied thoroughly every two hours when exposed to sunlight.
