China holds the potential to lead a global upgrade of sanitation solutions, public health advocates said during the Reinvented Toilet Expo that closed in Beijing on Thursday.

The three-day expo, launched by the Bill and Melinda Gates Foundation, aimed to showcase and promote a new generation of toilet technologies, concepts and management systems.

China is ready to engage in the $6 billion global market thanks to its "toilet revolution" campaign and domestic companies' investment in developing key technologies, according to public health experts and enterprise representatives at the expo.

"In recent decades, China has made great progress in improving health and sanitation for hundreds of millions of people," Microsoft founder and billionaire philanthropist Bill Gates said on the opening day of the expo on Tuesday.

He said President Xi Jinping's toilet revolution had underscored China's commitment to accelerating progress on safe sanitation.

Gates jolted those listening to his speech in the conference hall by holding a beaker of human feces on stage, pointing out that it could contain 200 trillion rotavirus cells, 20 billion shigella bacteria, and 100,000 parasitic worm eggs.

He said it was notable that three of the 20 exhibitors at the expo were based in China, which highlighted the country's interest in adopting innovative sanitation technology for the domestic and global markets.

Data from the World Health Organization shows that 2.3 billion people around the world don't have access to basic sanitation facilities.

Untreated human waste is responsible for 500,000 infant deaths a year and $223 billion in medical costs, lost productivity and lost wages linked to diseases caused by poor water quality, sanitation and hygiene, according to the foundation.

Despite China's impressive improvement of its toilet systems, more efforts are needed in terms of the treatment of fecal sludge, which is usually buried underground, said Liu Dong, a senior program officer at the foundation's China office.

He called for a smarter and more technical approach to dealing with fecal sludge as areas for waste burial became harder to find.

Since China rolled out the toilet revolution campaign in 2015, more than half the toilets in rural areas have been renovated, and more than 87,000 newly built or renovated restrooms have opened at tourist attractions in the past three years.

At a meeting last month, Han Changfu, minister of agriculture and rural affairs, highlighted the need for enhanced technological support to overcome issues hampering the nationwide refurbishment of toilets.

Gilbert Ghostine, CEO of Firmenich, a fragrance and flavor company that introduced a malodor-control product at expo, said he is a strong believer in China's capability to commercialize sanitation products.

He said the campaign not only benefits residents in rural areas but also improves China's global reputation, as the country is a major tourism destination.

The expo, he added, had given his company an opportunity to find partners interested in tackling sanitation together, including a Chinese company in Suzhou, Jiangsu province.